Lumentum (LITE) 10-Q 2 May 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares shares in Millions	9 Months Ended
	Mar. 31, 2018	Apr. 27, 2018
Document and Entity Information
Entity Registrant Name	Lumentum Holdings Inc.
Entity Central Index Key	1,633,978
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--06-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		62.6
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Income Statement [Abstract]
Net revenue	$ 298.8	$ 255.8	$ 946.6	$ 778.9
Cost of sales	201	172	607.6	523
Amortization of acquired developed technologies	0.8	1.7	2.4	5.1
Gross profit	97	82.1	336.6	250.8
Operating expenses:
Research and development	38.2	37.3	118.3	112.9
Selling, general and administrative	33.2	28.1	95.5	84.2
Restructuring and related charges	0.1	3.1	3.8	10
Total operating expenses	71.5	68.5	217.6	207.1
Income from operations	25.5	13.6	119	43.7
Unrealized loss on derivative liabilities	(20.7)	(56.6)	(8.6)	(74.5)
Interest and other income (expense), net	(2.1)	(1.4)	(8.7)	(1.4)
Income (loss) before income taxes	2.7	(44.4)	101.7	(32.2)
Provision for (benefit from) income taxes	0	11.6	(112.9)	15.4
Net income (loss)	2.7	(56)	214.6	(47.6)
Cumulative dividends on Series A Preferred Stock	(0.2)	(0.2)	(0.7)	(0.6)
Earnings allocated to Series A Preferred Stock	(0.1)	0	(4.9)	0
Net income (loss) attributable to common stockholders	$ 2.4	$ (56.2)	$ 209	$ (48.2)
Net income (loss) per share attributable to common stockholders:
Basic (usd per share)	$ 0.04	$ (0.92)	$ 3.37	$ (0.80)
Diluted (usd per share)	$ 0.04	$ (0.92)	$ 3.31	$ (0.80)
Shares used in per share calculation attributable to common stockholders
Basic (in shares)	62.4	61	62.1	60.4
Diluted (in shares)	63.3	61	63.2	60.4

CONDENSED CONSOLIDATED STATEME3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 2.7	$ (56)	$ 214.6	$ (47.6)
Other comprehensive income (loss):
Net change in cumulative translation adjustment, net of tax	(0.1)	1.9	1.9	(2.7)
Net change in unrealized loss on available-for-sale securities, net of tax	(1.3)	0	(2)	0
Net change in accumulated other comprehensive income (loss)	(1.4)	1.9	(0.1)	(2.7)
Comprehensive income (loss)	$ 1.3	$ (54.1)	$ 214.5	$ (50.3)

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2018	Jul. 01, 2017
Current assets:
Cash and cash equivalents	$ 176.8	$ 272.9
Short-term investments	516	282.4
Accounts receivable, net	164.7	166.3
Inventories	144.2	145.2
Prepayments and other current assets	63	63.5
Total current assets	1,064.7	930.3
Property, plant and equipment, net	301.8	273.5
Goodwill and intangibles, net	19.9	21.5
Deferred income taxes	128.2	3.9
Other non-current assets	3.6	3.7
Total assets	1,518.2	1,232.9
Current liabilities:
Accounts payable	100.9	114.8
Accrued payroll and related expenses	33.2	27.5
Income taxes payable	0.1	0.7
Accrued expenses	36.3	19.3
Other current liabilities	21	21.9
Total current liabilities	191.5	184.2
Convertible notes	329.9	317.5
Derivative liability	60.2	51.6
Other non-current liabilities	24.2	25
Total liabilities	605.8	578.3
Commitments and contingencies (Note 16)
Redeemable convertible preferred stock:
Total redeemable convertible preferred stock	35.8	35.8
Stockholders’ equity:
Common stock, $0.001 par value, 990,000,000 authorized shares, 62,588,096 and 61,476,103 shares issued and outstanding as of March 31, 2018 and July 1, 2017, respectively	0.1	0.1
Additional paid-in capital	736	694.5
Retained earnings	133.2	(83.2)
Accumulated other comprehensive income	7.3	7.4
Total stockholders’ equity	876.6	618.8
Total liabilities, redeemable convertible preferred stock, and stockholders’ equity	1,518.2	1,232.9
Convertible Series A Preferred Stock
Redeemable convertible preferred stock:
Non-controlling interest redeemable convertible Series A Preferred Stock, $0.001 par value, 10,000,000 authorized shares; 35,805 shares issued and outstanding as of March 31, 2018 and July 1, 2017	35.8	$ 35.8
Total redeemable convertible preferred stock	$ 35.8

CONDENSED CONSOLIDATED BALANCE5

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2018	Jul. 01, 2017
Common stock, par value (usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized	990,000,000	990,000,000
Common stock, shares issued	62,588,096	61,476,103
Common stock, shares outstanding	62,588,096	61,476,103
Convertible Series A Preferred Stock
Non-controllable interest, preferred stock, par value (usd per share)	$ 0.001	$ 0.001
Non-controllable interest, preferred stock, shares authorized	10,000,000	10,000,000
Non-controllable interest, preferred stock, shares issued	35,805	35,805
Non-controllable interest, preferred stock, shares outstanding	35,805	35,805

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017
OPERATING ACTIVITIES:
Net income (loss)	$ 214.6	$ (47.6)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation expense	53.3	39.1
Stock-based compensation	35.1	24.7
Unrealized loss on derivative liabilities	8.6	74.5
Amortization of acquired developed technologies and other intangibles	2.4	5.4
Loss on retirement of equipment	0.5	0
Excess tax benefit associated with stock-based compensation	0	(5.2)
Amortization of discount on 0.25% Convertible Senior Notes due 2024	12.4	1
Release of valuation allowance, net	(124)	0
Other non-cash (income) expenses	0.3	0
Changes in operating assets and liabilities:
Accounts receivable	1.6	(14.9)
Inventories	1.1	(14)
Prepayments and other current and non-currents assets	1.9	(7.9)
Income taxes, net	(0.5)	15.4
Accounts payable	(15.9)	(18.2)
Accrued payroll and related expenses	5.6	4.5
Accrued expenses and other current and non-current liabilities	12.9	15.1
Net cash provided by operating activities	209.9	71.9
INVESTING ACTIVITIES:
Purchase of property, plant and equipment	(72.9)	(100)
Purchases of short-term investments	(585.1)	0
Proceeds from maturities and sales of short-term investments	349.3	0
Acquisition of business, net of cash acquired	0	(5.1)
Net cash used in investing activities	(308.7)	(105.1)
FINANCING ACTIVITIES:
Proceeds from the issuance of 0.25% Convertible Senior Notes due 2024, net of issuance costs	0	443.2
Excess tax benefit associated with stock-based compensation	0	5.2
Payment of dividends - preferred stock	(0.7)	(0.6)
Proceeds from employee stock plans	4.4	3.7
Repayment of capital lease obligation	(3.5)	0
Proceeds from the exercise of stock options	1.7	3.2
Net cash provided by financing activities	1.9	454.7
Effect of exchange rates on cash and cash equivalents	0.8	(0.7)
Increase (decrease) in cash and cash equivalents	(96.1)	420.8
Cash and cash equivalents at beginning of period	272.9	157.1
Cash and cash equivalents at end of period	176.8	577.9
Supplemental disclosure of cash flow information:
Cash paid for taxes	11.5	8.3
Cash paid for interest	1.2	0
Unpaid property, plant and equipment in accounts payable and accrued expenses	10.5	15.2
Equipment acquired under capital lease	15.6	0
Issuance costs in current liabilities	$ 0	$ 0.9

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	9 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Summary of Significant Accounting Policies	Note 1. Description of Business and Summary of Significant Accounting Policies Description of Business Lumentum (we, us, our or the Company) is an industry-leading provider of optical and photonic products defined by revenue and market share addressing a range of end market applications including Optical Communications (“OpComms”) and Commercial Lasers (“Lasers”) for manufacturing, inspection and life-science applications. We seek to use our core optical and photonic technology and our volume manufacturing capability to expand into attractive emerging markets that benefit from advantages that optical or photonics-based solutions provide, including 3D sensing for consumer electronics and diode light sources for a variety of consumer and industrial applications. The majority of our customers tend to be original equipment manufacturers (“OEMs”) that incorporate our products into their products which then address end-market applications. For example, we sell fiber optic components that our network equipment manufacturer (“NEM”) customers assemble into communications networking systems, which they sell to network service providers or enterprises with their own networks. Similarly, many of our customers for our Lasers products incorporate our products into tools they produce, which are used for manufacturing processes by their customers. For 3D sensing, we sell diode lasers to manufacturers of consumer electronics products for mobile, personal computing, gaming, and other applications, who then integrate our devices within their products, for eventual resale to consumers. Basis of Presentation The preparation of the condensed consolidated financial statements in accordance with U.S. generally accepted accounting principles (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported in our condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and various other assumptions believed to be reasonable. Although these estimates are based on management’s best knowledge of current events and actions that may impact the Company in the future, actual results may be different from the estimates. Our critical accounting policies are those that affect our financial statements materially and involve difficult, subjective or complex judgments by management. Those policies are revenue recognition, inventory valuation, derivative liability valuation, long-lived asset valuation, warranty and accounting for income taxes. On March 11, 2018, Lumentum and Oclaro, Inc. ("Oclaro") entered into a Merger Agreement (the “Merger Agreement”), unanimously approved by the boards of directors of both companies, under which Lumentum will acquire all outstanding shares of Oclaro common stock. Each share of Oclaro common stock will be exchanged for $5.60 in cash and 0.0636 shares of Lumentum common stock, subject to the terms of the Merger Agreement. The total transaction consideration was approximately $1.8 billion as of the date of the Merger Agreement. Oclaro stockholders will own approximately 16% of the combined company at closing. The Merger Agreement contains certain termination rights for both Lumentum and Oclaro. The Merger Agreement further provides that upon termination of the Merger Agreement under specified circumstances relating to failure to obtain regulatory approvals, Lumentum may be required to pay Oclaro a termination fee of $80 million . The total transaction consideration will be funded by a combination of cash from the combined company of approximately $416 million , $550 million in new debt, and $859 million in Lumentum common stock. Lumentum entered into a commitment letter with Deutsche Bank Securities Inc. and Deutsche Bank AG New York, New York Branch (“Deutsche Bank”), pursuant to which, subject to the terms and conditions set forth therein, Deutsche Bank has committed to provide a senior secured term loan facility in an aggregate principal amount of $550 million , with a provision for additional senior secured term loans in an aggregate principal amount not to exceed $250 million . The transaction is subject to customary closing conditions, including the approval of Oclaro stockholders and antitrust regulatory approval in the United States and China. Under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”), Lumentum and Oclaro are required to make pre-merger notification filings and to await the expiration or early termination of the statutory waiting period prior to completing the Merger. Lumentum and Oclaro submitted pre-merger notification filings under the HSR Act on March 23, 2018 and received early termination of the waiting period on April 4, 2018. The transaction is not subject to any financing condition. The transaction is expected to be completed in the second half of calendar 2018. Fiscal Years We utilize a 52-53 week fiscal year ending on the Saturday closest to June 30th. Our fiscal 2018 is a 52-week year ending on June 30, 2018 . Our fiscal 2017 was a 52-week year and ended on July 1, 2017 . Principles of Consolidation These interim unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All inter-company transactions and balances have been eliminated in consolidation. Accounting Policies The accompanying interim unaudited condensed consolidated financial statements and accompanying related notes should be read in conjunction with the audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the fiscal year ended July 1, 2017 . Effective July 2, 2017, we adopted Accounting Standards Update (“ASU”) 2016-09, Stock Compensation ASU 718 - Improvements to Employee Share-Based Payment Accounting . As a result of the adoption, in the first quarter of fiscal year 2018, we recorded on a modified retrospective basis a $2.6 million cumulative-effect adjustment to retained earnings for the recognition of excess tax benefits generated by the settlement of share-based awards in prior periods. We elected to account for forfeitures of equity awards when they occur. The change was applied on a modified retrospective basis with a cumulative-effect adjustment of approximately $0.2 million to retained earnings in the fiscal first quarter of 2018. All excess tax benefits and deficiencies are recognized in the income tax provision in the condensed consolidated statements of operations prospectively, rather than in additional paid-in-capital in the condensed consolidated balance sheets. In addition, the standard eliminates the requirement to defer recognition of excess tax benefits until they are realized through a reduction to income taxes payable. We present excess tax benefits as an operating activity in the condensed consolidated statements of cash flows on a prospective basis.

Recently Issued Accounting Pron

Recently Issued Accounting Pronouncements	9 Months Ended
	Mar. 31, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recently Issued Accounting Pronouncements	Note 2. Recently Issued Accounting Pronouncements In January 2017, the Financial Accounting Standards Board (“FASB”) issued ASU 2017-01, Business Combinations (Topic 805) , which clarifies the definition of a business. For accounting and financial reporting purposes, businesses are generally comprised of three elements; inputs, processes, and outputs. Integrated sets of assets and activities capable of providing these three elements may not always be considered a business, and the lack of one of the three elements does not always disqualify the set from being a business. The issuance of ASU 2017-01 provides a clarifying screen to determine when a set of assets and activities is not a business. Primarily, the screen requires that when substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets, the set is not a business. The amendments contained in ASU 2017-01 are effective for annual periods beginning after December 15, 2017, including interim periods within those periods. The accounting standard update will be effective for us beginning in the first quarter of fiscal 2019 and should be applied prospectively. We do not believe the implementation of ASU 2017-01 will have a material impact on our condensed consolidated financial statements. In January 2017, FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Accounting for Goodwill Impairment . ASU 2017-04 removes the requirement to perform a hypothetical purchase price allocation to measure goodwill impairment. A goodwill impairment charge will be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The amendments contained in ASU 2017-04 are effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted, which should be applied prospectively. We plan to adopt the accounting standard update in our first quarter of fiscal 2019. We do not believe the implementation of ASU 2017-04 will have a material impact on our condensed consolidated financial statements. In August 2016, FASB issued ASU 2016-15, S tatement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments , which clarifies how companies present and classify certain cash receipts and cash payments in the statement of cash flows. The amendments contained in ASU 2016-15 are effective for interim and annual periods beginning after December 15, 2017. The accounting standard update will be effective for us in the first quarter of fiscal 2019 and will be applied prospectively. If we elect to settle the principal amounts of our 2024 Notes (refer to “ Note 10. Convertible Senior Notes ”) in cash, the payment will be bifurcated between (i) cash outflows for operating activities of $137.6 million for the portion related to accreted interest attributable to debt discount, and (ii) financing activities for the remainder of $312.4 million . In February 2016, FASB issued ASU 2016-02, Leases. The new guidance generally requires an entity to recognize on its balance sheet operating and financing lease liabilities and corresponding right-of-use assets. The new guidance contained in ASU 2016-02 is effective for annual periods beginning after December 15, 2018, including interim periods within those periods, with early adoption permitted. The standard is effective for us in our first quarter of fiscal 2020 and should be applied prospectively. Based on our current lease portfolio, we estimate the value of leased assets and liabilities that may be recognized will be material. We are continuing to evaluate the impact of ASU 2016-02 and is subject to change. In May 2014, FASB issued ASU 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which amended the existing accounting standards for revenue recognition. ASU 2014-09 establishes principles for recognizing revenue upon the transfer of promised goods or services to customers, in an amount that reflects the consideration expected to be received in exchange for those goods or services. The new standard requires that reporting companies disclose the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. On July 9, 2015, FASB agreed to delay the effective date by one year, and accordingly, the new standard is effective for us at the beginning of the first quarter of fiscal 2019. The guidance to ASU 2014-09 permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (modified retrospective method). We selected the modified retrospective method. We do not anticipate that the adoption of ASU 2014-09 will have a material impact on our consolidated financial statements including the potential impact of the additional disclosure requirement, primarily because we will continue to recognize most revenue at a point-in-time when control transfers. This is similar to the current revenue recognition model. We currently recognize revenue when all four revenue recognition criteria have been met: (i) persuasive evidence of an arrangement exists, (ii) the product has been delivered or the service has been rendered, (iii) the price is fixed or determinable and (iv) collection is reasonably assured. Revenue from product sales is recorded when all of the foregoing conditions are met and risk of loss and title passes to the customer. Our products typically include a warranty and the estimated cost of product warranty claims, based on historical experience, is recorded at the time the sale is recognized. Sales to customers are generally not subject to price protection or return rights. The majority of our sales are made to OEMs, distributors, resellers and end-users. We are implementing changes to our accounting policies, internal controls, and disclosures to support the new standard; however, these changes will not be material.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Note 3. Earnings Per Share The following table sets forth the computation of basic and diluted net income (loss) attributable to common stockholders per share ( in millions, except per share data ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Basic Earnings per Common Share Net income (loss) $ 2.7 $ (56.0 ) $ 214.6 $ (47.6 ) Less: Cumulative dividends on Series A Preferred Stock (0.2 ) (0.2 ) (0.7 ) (0.6 ) Less: Earnings allocated to Series A Preferred Stock (0.1 ) — (4.9 ) — Net income (loss) attributable to common stockholders - basic $ 2.4 $ (56.2 ) $ 209.00 $ (48.2 ) Weighted average common shares outstanding including Series A Preferred Stock 63.9 62.5 63.6 61.9 Less: Weighted average Series A Preferred Stock (1.5 ) (1.5 ) (1.5 ) (1.5 ) Basic weighted average common shares outstanding 62.4 61.0 62.1 60.4 Net income (loss) per share attributable to common stockholders - basic $ 0.04 $ (0.92 ) $ 3.37 $ (0.80 ) Diluted Earnings per Common Share Net income (loss) attributable to common stockholders - diluted $ 2.4 $ (56.2 ) $ 209.0 $ (48.2 ) Weighted average common shares outstanding for basic earnings per common share 62.4 61.0 62.1 60.4 Effect of dilutive securities from stock-based benefit plans 0.9 — 1.1 — Effect of diluted securities from Series A Preferred Stock — — — — Diluted weighted average common shares outstanding 63.3 61.0 63.2 60.4 Net income (loss) per share attributable to common stockholders - diluted $ 0.04 $ (0.92 ) $ 3.31 $ (0.80 ) Our Series A Preferred Stock is considered a participating security, which may participate in undistributed earnings with our common stock. The holders of our Preferred Stock would be entitled to share in dividends, on an as-converted basis, if the holders of our common stock were to receive dividends. We are required to use the two-class method when computing earnings per share as we have a security that qualifies as a participating security. The two-class method is an earnings allocation formula that determines earnings per share for each class of common stock and participating security according to dividends declared (or accumulated) and participation rights in undistributed earnings. In determining the amount of net earnings to allocate to common stockholders, earnings are allocated to both common and participating securities based on their respective weighted-average shares outstanding during the period. Diluted earnings per common share, when applicable, is computed using the more dilutive of the two-class method or the if-converted method. In periods of net loss, no effect is given to participating securities since they do not contractually participate in the losses of the Company. The dilutive effect of stock-based awards is reflected in diluted earnings per share by application of the treasury stock method, which includes consideration of unamortized share-based compensation expense and the dilutive effect of in-the-money options and non-vested restricted stock units. Under the treasury stock method, the amount the employee must pay for exercising stock options and unamortized share-based compensation expense collectively are assumed proceeds to be used to repurchase hypothetical shares. An increase in the fair value of our common stock can result in a greater dilutive effect from potentially dilutive awards. In March 2017, we issued $450 million in aggregate principal amount of 0.25% Convertible Senior Notes due in 2024 (the “2024 Notes”). We have the ability and intent to settle the $450 million face value of the 2024 Notes in cash. Therefore, we use the treasury stock method for calculating the dilutive impact of the 2024 Notes. The 2024 Notes will have no impact to diluted earnings per share until the average price of our common stock exceeds the conversion price of $60.62 . Refer to “ Note 10. Convertible Senior Notes ” for further discussion. For the three and nine months ended March 31, 2018 and April 1, 2017 , the number of shares related to our stock-based benefit plans that were excluded from the calculation of diluted shares was not material.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Mar. 31, 2018
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Accumulated Other Comprehensive Income (Loss)	Note 4. Accumulated Other Comprehensive Income (Loss) Our accumulated other comprehensive income (loss) consists of the accumulated net unrealized gains or losses on foreign currency translation adjustments, the defined benefit obligation, and available-for-sale securities. As of March 31, 2018 and July 1, 2017 , balances for the components of accumulated other comprehensive income (loss) were as follows ( in millions ): Foreign currency translation adjustments, net of tax Defined benefit obligation, net of tax Unrealized gain (loss) on available-for-sale securities, net of tax Total Beginning balance as of July 1, 2017 $ 10.5 $ (3.1 ) $ — $ 7.4 Other comprehensive income (loss) 1.9 — (2.0 ) (0.1 ) Ending balance as of March 31, 2018 $ 12.4 $ (3.1 ) $ (2.0 ) $ 7.3 We evaluate the assumptions over the fair value of our defined benefit obligation annually and make changes as necessary.

Asset Acquisition

Asset Acquisition	9 Months Ended
	Mar. 31, 2018
Asset Acquisition [Abstract]
Asset Acquisition	Note 5. Asset Acquisition On March 30, 2018, we entered into a Transition Services Agreement (“TSA”) with one of our contract manufacturers to wind down the production of our products at their facility in China and to facilitate an orderly transition of manufacturing to our manufacturing facility in Thailand, including the purchase of the manufacturing equipment. Under the terms of the TSA, we are required to pay $5.3 million in cash upon completion of certain milestones related to the purchase of equipment. We are also required to share cost of retention and severance, and to reimburse for certain other direct and indirect costs incurred by our contract manufacturer for transition services provided. These costs will be expensed as incurred.

Balance Sheet Details

Balance Sheet Details	9 Months Ended
	Mar. 31, 2018
Balance Sheet and Other Details
Balance Sheet Details	Note 6. Balance Sheet Details Accounts receivable allowances As of March 31, 2018 and July 1, 2017 , our accounts receivable allowance balance was $ 1.8 million and $1.8 million , respectively. Inventories The components of inventories were as follows ( in millions ): March 31, 2018 July 1, 2017 Finished goods $ 93.2 $ 71.7 Work in process 30.5 49.4 Raw materials and purchased parts 20.5 24.1 Inventories $ 144.2 $ 145.2 Prepayments and other current assets The components of prepayments and other current assets were as follows ( in millions ): March 31, 2018 July 1, 2017 Capitalized manufacturing overhead $ 23.9 $ 30.1 Prepayments 14.8 12.3 Advances to contract manufacturers 15.0 10.5 Other current assets 9.3 10.6 Prepayments and other current assets $ 63.0 $ 63.5 Property , plant and equipment, net The components of property, plant and equipment, net were as follows ( in millions ): March 31, 2018 July 1, 2017 Land $ 10.6 $ 10.6 Buildings and improvement 49.3 37.3 Machinery and equipment (1) 543.2 461.1 Computer equipment and software 37.3 31.2 Furniture and fixtures 4.9 4.6 Leasehold improvements 30.1 30.5 Construction in progress 63.2 84.6 738.6 659.9 Less: Accumulated depreciation (436.8 ) (386.4 ) Property, plant and equipment, net $ 301.8 $ 273.5 (1) In the first quarter of fiscal 2018, we started leasing equipment from a vendor and have accounted for the transaction as a capital lease. Included in the table above is our capital lease asset of $11.9 million , net of depreciation expense of $3.7 million as of March 31, 2018 . During the three and nine months ended March 31, 2018 , we recorded depreciation expense of $18.4 million and $53.3 million , respectively. During the three and nine months ended April 1, 2017 , we recorded a depreciation expense of $14.1 million and $39.1 million , respectively. Our construction in progress primarily includes machinery and equipment that were purchased in order to increase our manufacturing capacity. We expect to place these assets in service in the next 12 months. Other current liabilities The components of other current liabilities were as follows (in millions) : March 31, 2018 July 1, 2017 Warranty accrual (1) $ 7.0 $ 9.7 Restructuring accrual and related charges (2) — 3.8 Deferred revenue and customer deposits 2.5 6.9 Capital lease obligation (3) 9.2 — Other current liabilities 2.3 1.5 Other current liabilities $ 21.0 $ 21.9 (1) Refer to “ Note 16. Commitments and Contingencies ” in the Notes to Unaudited Condensed Consolidated Financial Statements. (2) Refer to “ Note 13. Restructuring and Related Charges ” in the Notes to Unaudited Condensed Consolidated Financial Statements. (3) As of March 31, 2018 , an amount of $2.3 million related to a capital lease was recorded in accounts payable on the condensed consolidated balance sheet. Refer to “ Note 16. Commitments and Contingencies ” in the Notes to Unaudited Condensed Consolidated Financial Statements. Other non-current liabilities The components of other non-current liabilities were as follows ( in millions ): March 31, 2018 July 1, 2017 Asset retirement obligation $ 2.7 $ 2.5 Pension and related accrual 3.2 3.9 Deferred rent 3.1 3.3 Unrecognized tax benefit 10.2 10.5 Capital lease obligation (1) 0.8 — Other non-current liabilities 4.2 4.8 Other non-current liabilities $ 24.2 $ 25.0 (1) Refer to “ Note 16. Commitments and Contingencies ” in the Notes to Unaudited Condensed Consolidated Financial Statements.

Cash, Cash Equivalents, and Sho

Cash, Cash Equivalents, and Short-term Investments	9 Months Ended
	Mar. 31, 2018
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents, and Short-term Investments	Note 7. Cash, Cash Equivalents, and Short-term Investments Cash, cash equivalents and short-term investments The following table summarizes our cash, cash equivalents, and short-term investments by category for the periods presented ( in millions ): Amortized Gross Gross Fair Value March 31, 2018: Cash $ 82.6 $ — $ — $ 82.6 Cash equivalents: Commercial paper 29.1 — — 29.1 Corporate debt securities 26.0 — — 26.0 Money market funds 2.5 — — 2.5 Municipal bonds 1.5 — — 1.5 Foreign government bonds 2.0 2.0 U.S. Treasury 26.7 — — 26.7 Asset-backed securities 6.4 — — 6.4 Total cash and cash equivalents $ 176.8 $ — $ — $ 176.8 Short-term investments: Certificates of deposit $ 32.0 $ — $ — $ 32.0 Commercial paper 35.1 — — 35.1 Asset-backed securities 114.3 — (0.3 ) 114.0 Corporate debt securities 317.6 0.1 (1.8 ) 315.9 Municipal bonds 6.2 — — 6.2 Mortgage-backed securities 4.8 — — 4.8 Foreign government bonds 8.0 — — 8.0 Total short-term investments $ 518.0 $ 0.1 $ (2.1 ) $ 516.0 July 1, 2017: Cash $ 201.3 $ — $ — $ 201.3 Cash equivalents: Certificates of deposit 52.1 — — 52.1 Commercial paper 14.7 — — 14.7 Money market funds 4.8 — — 4.8 Total cash and cash equivalents $ 272.9 $ — $ — $ 272.9 Short-term investments: Certificates of deposit $ 202.1 $ — $ — $ 202.1 Asset-backed securities 26.1 — — 26.1 Corporate debt securities 46.4 — — 46.4 Municipal bonds 4.9 — — 4.9 Foreign government bonds 1.0 — — 1.0 U.S. Treasury 1.9 — — 1.9 Total short-term investments $ 282.4 $ — $ — $ 282.4 We use the specific-identification method to determine any realized gains or losses from the sale of our short-term investments classified as available-for-sale. During the three and nine months ended March 31, 2018 , we did not realize significant gains or losses on a gross level from the sale of our short-term investments classified as available-for-sale. The following table summarizes unrealized losses on our cash equivalents and short-term investments by category and length of time the investment has been in a continuous unrealized loss position as of the periods presented (in millions) : Less than 12 months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses March 31, 2018: Certificates of deposit $ 25.4 $ — $ — $ — $ 25.4 $ — Commercial paper 39.7 — — — 39.7 — Asset-backed securities 112.9 (0.3 ) — — 112.9 (0.3 ) Corporate debt securities 291.8 (1.8 ) — — 291.8 (1.8 ) Municipal bonds 6.2 — — — 6.2 — Mortgage-backed securities 4.5 — — — 4.5 — U.S. Treasury 3.0 — — — 3.0 — Foreign government bonds 8.8 — — — 8.8 — Total $ 492.3 $ (2.1 ) $ — $ — $ 492.3 $ (2.1 ) July 1, 2017: Asset-backed securities $ 21.5 $ — $ — $ — $ 21.5 $ — Corporate debt securities 29.8 — — — 29.8 — Municipal bonds 2.9 — — — 2.9 — Foreign government bonds 1.0 — — — 1.0 — U.S. Treasury 1.9 — — — 1.9 — Total $ 57.1 $ — $ — $ — $ 57.1 $ — The following table classifies our investments in debt securities by contractual maturities ( in millions ): As of March 31, 2018 Amortized Cost Fair Value Due in 1 year $ 252.1 $ 251.5 Due in 1 year through 5 years 252.7 251.3 Due in 5 years through 10 years 7.2 7.2 Due after 10 years 6.0 6.0 $ 518.0 $ 516.0 All available-for-sale securities have been classified as current, based on management’s intent and ability to use the funds in current operations.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 8. Fair Value Measurements We determine fair value based on the fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value assumes that the transaction to sell the asset or transfer the liability occurs in the principal or most advantageous market for the asset or liability and establishes that the fair value of an asset or liability shall be determined based on the assumptions that market participants would use in pricing the asset or liability. The classification of a financial asset or liability within the hierarchy is based upon the lowest level input that is significant to the fair value measurement. The fair value hierarchy prioritizes the inputs into three levels that may be used to measure fair value: Level 1: Inputs are unadjusted quoted prices in active markets for identical assets or liabilities. Level 2: Inputs are quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. Level 3: Inputs are unobservable inputs based on our assumptions. The fair value of the Company’s Level 1 financial instruments, such as money market funds, which are traded in active markets, is based on quoted market prices for identical instruments. The fair value of the Company’s Level 2 fixed income securities is obtained from an independent pricing service, which may use quoted market prices for identical or comparable instruments or model driven valuations using observable market data or inputs corroborated by observable market data. Our marketable securities are held by custodians who obtain investment prices from a third-party pricing provider that incorporates standard inputs in various asset price models. The Company’s procedures include controls to ensure that appropriate fair values are recorded, including comparing the fair values obtained from the Company’s pricing service against fair values obtained from another independent source. We estimate the fair value of the embedded derivative for the Series A Preferred Stock using the binomial lattice model. The lattice model requires the various assumptions to be made to determine the fair value of the embedded derivatives. These assumptions represent Level 3 inputs. Refer to “ Note 11. Derivative Liability ” in the Notes to Unaudited Condensed Consolidated Financial Statements. In February 2017, we completed the acquisition of a privately held company to enhance our manufacturing and vertical integration capabilities for a total purchase consideration of $8.7 million . We estimated the fair value of our Level 3 contingent consideration related to this acquisition at the present value of the expected contingent payments, determined using a probabilistic approach. We are required to reassess the fair value of contingent payments on a periodic basis. During the three months ended April 1, 2017 , we estimated the likelihood of meeting the production targets at 90 percent . There was no change in the fair value of our contingent consideration during the three and nine months ended March 31, 2018 . The fair value of such contingent consideration is recorded in accrued liabilities on the condensed consolidated balance sheet as of March 31, 2018 . This contingent consideration will result in a cash payment of $3.0 million , if and when the production targets are achieved, which we expect to occur within 36 months following the acquisition date. Our pension assets consist of multiple institutional funds (“pension funds”) of which the fair values are based on the quoted prices of the underlying funds. Pension funds are classified as Level 2 assets since such funds are not directly traded in active markets. Financial assets and liabilities measured at fair value on a recurring basis are summarized below ( in millions ): Level 1 Level 2 Level 3 Total March 31, 2018: Assets: Cash equivalents: Commercial paper $ — $ 29.1 $ — $ 29.1 Corporate debt securities — 26.0 — 26.0 Money market funds 2.5 — — 2.5 Municipal bonds — 1.5 — 1.5 Foreign government bonds — 2.0 — 2.0 U.S. Treasury 26.7 — — 26.7 Asset-backed securities — 6.4 — 6.4 Short-term investments: Certificates of deposit — 32.0 — 32.0 Commercial paper — 35.1 — 35.1 Asset-backed securities — 114.0 — 114.0 Corporate debt securities — 315.9 — 315.9 Municipal bonds — 6.2 — 6.2 Mortgage-backed securities — 4.8 — 4.8 Foreign government bonds — 8.0 — 8.0 Total assets $ 29.2 $ 581.0 $ — $ 610.2 Other accrued liabilities: Derivative liability $ — $ — $ 60.2 $ 60.2 Acquisition contingencies — — 2.7 2.7 Total other accrued liabilities $ — $ — $ 62.9 $ 62.9 Level 1 Level 2 Level 3 Total July 1, 2017: Assets: Cash equivalents: Certificates of deposit $ — $ 52.1 $ — $ 52.1 Commercial paper — 14.7 — 14.7 Money market funds 4.8 — — 4.8 Short-term investments: Certificates of deposit — 202.1 — 202.1 Asset-backed securities — 26.1 — 26.1 Corporate debt securities — 46.4 — 46.4 Municipal bonds — 4.9 — 4.9 Foreign government bonds — 1.0 — 1.0 U.S. Treasury 1.9 — — 1.9 Total assets $ 6.7 $ 347.3 $ — $ 354.0 Other accrued liabilities: Derivative liability $ — $ — $ 51.6 $ 51.6 Acquisition contingencies — — 2.7 2.7 Total other accrued liabilities $ — $ — $ 54.3 $ 54.3 Assets Measured at Fair Value on a Non-Recurring Basis We periodically review our intangible and other long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Determination of recoverability is based on the lowest level of identifiable estimated undiscounted cash flows resulting from use of the asset and its eventual disposition. If not recoverable, an impairment loss would be calculated based on the excess of the carrying amount over the fair value. Management utilizes various valuation methods, including an income approach, a market approach and a cost approach, to estimate the fair value of intangible and other long-lived assets. During the annual impairment testing performed in fiscal 2017, all our intangible and other long-lived assets passed Step 1. No impairment charges were recorded in fiscal 2017 or during the three and nine months ended March 31, 2018 . Refer to “ Note 12. Goodwill and Other Intangible Assets ”.

Non-Controlling Interest Redeem

Non-Controlling Interest Redeemable Convertible Preferred Stock	9 Months Ended
	Mar. 31, 2018
Temporary Equity Disclosure [Abstract]
Non-Controlling Interest Redeemable Convertible Preferred Stock	Note 9. Non-Controlling Interest Redeemable Convertible Preferred Stock On July 31, 2015, our wholly-owned subsidiary, Lumentum Inc., issued 40,000 shares of its Series A Preferred Stock to Viavi Solutions Inc. (“Viavi”). Pursuant to a securities purchase agreement between the Company, Viavi and Amada Holdings Co., Ltd. (“Amada”), 35,805 shares of Series A Preferred Stock were sold by Viavi to Amada in August 2015. The remaining 4,195 shares of the Series A Preferred Stock were canceled. The Series A Preferred Stock is referred to as our Non-Controlling Interest Redeemable Convertible Preferred Stock within these condensed consolidated financial statements. The Series A Preferred Stock is redeemable at the option of Amada after five years and classified as non-controlling interest redeemable convertible preferred stock in our condensed consolidated balance sheet. The Series A Preferred Stock is measured at its redemption value. The Series A Preferred Stock value of $35.8 million as of March 31, 2018 has not changed from the prior year. The Series A Preferred Stock conversion feature is bifurcated from the Series A Preferred Stock and accounted for separately as a derivative liability. The derivative liability is measured at fair value each reporting period with the change in fair value recorded in the condensed consolidated statements of operations. Refer to “ Note 11. Derivative Liability ”. The following paragraphs describe the terms and conditions of the Series A Preferred Stock: Conversion The Series A Preferred Stock is convertible, at the option of the holder, into shares of our common stock commencing on the second anniversary of the closing of the securities purchase (absent a change of control of us or similar event) using a conversion price of $24.63 , which is equal to 125% of the volume weighted average price per share of our common stock in the five “regular-way” trading days following our separation from JDS Uniphase Corporation (“JDSU” and now, Viavi) in August 2015 (the “Separation”). Liquidation Upon any liquidation, dissolution, or winding up of our business, whether voluntary or involuntary, holders of Series A Preferred Stock will be entitled to receive, in preference to holders of common stock or any other class or series of our outstanding capital stock ranking in any such event junior to the Series A Preferred Stock, an amount per share equal to the greater of (i) the Issuance Value of $1,000 per share for Series A Preferred Stock plus all accrued and unpaid dividends thereon (whether or not authorized or declared) through the date of payment and (ii) the amount as would have been payable had all Series A Preferred Stock been converted into common stock immediately prior to such liquidation event. If upon occurrence of any such event, our assets legally available for distribution are insufficient to permit payment of the aforementioned preferential amounts, then all of our assets legally available for distribution will be distributed ratably to the holders of the Series A Preferred Stock and to the holders of any other class or series of our capital stock ranking on parity with the Series A Preferred Stock. Voting Rights The shares of Series A Preferred Stock have no voting rights except as follows: • Authorize, approve, or make any change to the powers, preferences, privileges or rights of the Series A Preferred Stock; • Authorize or issue any additional shares of Series A Preferred Stock or reduce the number of shares of Series A Preferred Stock; or • Create, or hold capital stock in, any subsidiary that is not wholly-owned by the Company. Dividends Holders of Series A Preferred Stock, in preference to holders of common stock or any other class or series of our outstanding capital stock ranking in any such event junior to the Series A Preferred Stock, are entitled to receive, when and as declared by the board of directors, quarterly cumulative cash dividends at the annual rate of 2.5% of the Issuance Value per share on each outstanding share of Series A Preferred Stock. The accrued dividends are payable on March 31, June 30, September 30 and December 31 of each year commencing on September 30, 2015. The accrued dividends as of March 31, 2018 and July 1, 2017 were $0.2 million and $0.2 million , respectively. Dividends paid were $0.5 million and $0.7 million for the three and nine months ended March 31, 2018 , respectively, and $0.2 million and $0.6 million for the three and nine months ended April 1, 2017 , respectively. Redemption Optional redemption by the Company On or after the third anniversary in August 2018, we will have the option to redeem for cash all (but not less than all) of the shares of Series A Preferred Stock at a redemption price equal to the Issuance Value plus the accrued and unpaid dividends on each share and any past due dividends, whether or not authorized or declared. Optional redemption by holders Commencing on the fifth anniversary of the Issuance Date of the Series A Preferred Stock, each holder of Series A Preferred Stock may cause the Company to redeem for cash any number of shares of Series A Preferred Stock on any date at a redemption price for share redeemed equal to the Issuance Value plus the accrued and unpaid dividends on each share and any past due dividends, whether or not authorized or declared.

Convertible Senior Notes

Convertible Senior Notes	9 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Convertible Senior Notes	Note 10. Convertible Senior Notes In March 2017, we issued the 2024 Notes in a private placement to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”). The 2024 Notes are governed by an indenture between the Company, as the issuer, and U.S. Bank National Association, as trustee (the “Indenture”). The 2024 Notes are unsecured and do not contain any financial covenants, restrictions on dividends, incurrence of senior debt or other indebtedness, or the issuance or repurchase of securities by us. The 2024 Notes bear interest at a rate of 0.25% per year. Interest on the 2024 Notes is payable semi-annually in arrears on March 15 and September 15 of each year, beginning on September 15, 2017. The 2024 Notes will mature on March 15, 2024, unless earlier repurchased by us or converted pursuant to their terms. The initial conversion rate of the 2024 Notes is 16.4965 shares of common stock per $1,000 principal amount of 2024 Notes, which is equivalent to an initial conversion price of approximately $60.62 per share, a 132.5% premium to the fair market value at the date of issuance. Prior to the close of business on the business day immediately preceding December 15, 2023, the 2024 Notes will be convertible only under the following circumstances: (1) during any fiscal quarter (and only during such fiscal quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on the last trading day of the immediately preceding fiscal quarter is greater than or equal to 130% of the applicable conversion price on each applicable trading day; (2) during the five consecutive business day period after any five consecutive trading day period (the “measurement period”) in which the trading price per $1,000 principal amount of notes for each trading day of such measurement period was less than 98% of the product of the last reported sale price of our common stock and the applicable conversion rate on each such trading day; or (3) upon the occurrence of specified corporate events. On or after December 15, 2023 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert their notes at any time. In addition, upon the occurrence of a make-whole fundamental change, we will, in certain circumstances, increase the conversion rate by a number of additional shares for a holder that elects to convert 2024 Notes in connection with such make-whole fundamental change. We may not redeem the 2024 Notes prior to their maturity date and no sinking fund is provided for the 2024 Notes. Upon the occurrence of a fundamental change, holders may require us to repurchase all or a portion of their 2024 Notes for cash at a price equal to 100% of the principal amount of the 2024 Notes to be repurchased, plus any accrued and unpaid interest. We considered the features embedded in the 2024 Notes other than the conversion feature, including the holders’ put feature, our call feature, and the make-whole feature, and concluded that they are not required to be bifurcated and accounted for separately from the host debt instrument. Prior to the Tax Matters Agreement settlement condition (“TMA settlement condition”), because we could only settle the 2024 Notes in cash, we determined that the conversion feature met the definition of a derivative liability. We separated the derivative liability from the host debt instrument based on the fair value of the derivative liability. As of the issuance date, March 8, 2017, the derivative liability fair value of $129.9 million was calculated using the binomial valuation approach. The residual principal amount of the 2024 Notes of $320.1 million before issuance costs was allocated to the debt component. We incurred approximately $7.7 million in transaction costs in connection with the issuance of the 2024 Notes. These costs were allocated to the debt component and recognized as a debt discount. We amortize the debt discount, including both the initial value of the derivative liability and the transaction costs, over the term of the 2024 Notes using the effective interest method. The effective interest rate of the 2024 Notes is 5.4% per year. As of March 31, 2018 , the remaining debt discount amortization period was 71 months. During the year ended July 1, 2017, we satisfied the TMA settlement conditions. As such, the value of the conversion option will no longer be marked to market and was reclassified to additional paid-in capital within stockholders’ equity on our condensed consolidated balance sheet. The value of the conversion option at the time of issuance will be treated as an original issue discount for purposes of accounting for the debt component of the notes. The debt component will accrete up to the principal amount over the expected term of the debt. These accounting standards do not affect the actual amount we are required to repay, and the amount shown in the table below for the notes is the aggregate principal amount of the notes and does not reflect the debt discount we will be required to recognize. As of March 31, 2018 , the 2024 Notes consisted of the following ( in millions ): Liability component: March 31, 2018 July 1, 2017 Principal $ 450.0 $ 450.0 Unamortized debt discount (120.1 ) (132.5 ) Net carrying amount of the liability component $ 329.9 $ 317.5 The following table sets forth interest expense information related to the 2024 Notes for the three and nine months ended March 31, 2018 : March 31, 2018 (in millions, except percentages) Three Months Ended Nine Months Ended Contractual interest expense $ 0.3 $ 0.9 Amortization of the debt discount 4.2 12.4 Total interest expense $ 4.5 $ 13.3 Effective interest rate on the liability component 5.4 % 5.4 % We have the ability and intent to settle the $450 million face value of the debt in cash. Therefore, we use the treasury stock method for calculating the dilutive impact of the debt. The 2024 Notes will have no impact to diluted earnings per share until the average price of our common stock exceeds the conversion price of $60.62 .

Derivative Liability

Derivative Liability	9 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Liability	Note 11. Derivative Liability We estimate the fair value of the embedded derivative for the Series A Preferred Stock using the binomial lattice model. We applied the lattice model to value the embedded derivative using a “with-and-without method,” where the value of the Series A Preferred Stock, including the embedded derivative, is defined as the “with”, and the value of the Series A Preferred Stock, excluding the embedded derivative, is defined as the “without”. The lattice model requires the following inputs: (i) the Company's common stock price; (ii) conversion price; (iii) term; (iv) yield; (v) recovery rate for the Series A Preferred Stock; (vi) estimated stock volatility; and (vii) risk-free rate. The fair value of the embedded derivative was determined using Level 3 inputs under the fair value hierarchy (unobservable inputs). Changes in the inputs into this valuation model have a material impact in the estimated fair value of the embedded derivative. For example, a decrease (increase) in the stock price and the volatility results in a decrease (increase) in the estimated fair value of the embedded derivative. The changes in the fair value of the bifurcated embedded derivative for the Series A Preferred Stock are primarily related to the change in the price of our common stock and are reflected in the condensed consolidated statements of operations as “Unrealized gain (loss) on derivative liabilities”. Unrealized loss on derivative liability for the Series A Preferred Stock amounted to $(20.7) million and $(8.6) million for the three and nine months ended March 31, 2018 , respectively, and $(17.9) million and $(35.8) million for the three and nine months ended April 1, 2017 , respectively. The following table provides a reconciliation of the fair value of the embedded derivative for the Series A Preferred Stock for the three and nine months ended March 31, 2018 and April 1, 2017 ( in millions ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Balance as of beginning of period $ (39.5 ) $ (28.2 ) $ (51.6 ) $ (10.3 ) Unrealized loss on the Series A Preferred Stock derivative liability (20.7 ) (17.9 ) (8.6 ) (35.8 ) Balance as of end of period $ (60.2 ) $ (46.1 ) $ (60.2 ) $ (46.1 ) The following table summarizes the assumptions used to determine the fair value of the embedded derivative for Series A Preferred Stock: March 31, 2018 July 1, 2017 Stock price $ 63.80 $ 57.05 Conversion price $ 24.63 $ 24.63 Expected term (years) 2.37 3.11 Expected annual volatility 50.0 % 47.5 % Risk-free rate 2.31 % 1.57 % Preferred yield 8.32 % 7.56 % Also, during the three and nine months ended April 1, 2017 , we recorded an unrealized loss on the derivate liability from the 2024 Notes. On June 29, 2017, we met the requirements to account for the conversion option of the 2024 Notes as equity and the conversion option is no longer marked to market. Refer to “ Note 10. Convertible Senior Notes ” in the Notes to Unaudited Condensed Consolidated Financial Statements. The following table provides a reconciliation of the fair value of the embedded derivative for the 2024 Notes for the three and nine months ended March 31, 2018 and April 1, 2017 ( in millions ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Balance as of beginning of period $ — $ — $ — $ — Fair value of the embedded derivative for the 2024 Notes at issuance — (129.9 ) — (129.9 ) Unrealized loss on the 2024 Notes derivative liability — (38.7 ) — (38.7 ) Balance as of end of period $ — $ (168.6 ) $ — $ (168.6 )

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Note 12. Goodwill and Other Intangible Assets Goodwill The following table presents the changes in goodwill by our reportable segments during the nine months ended March 31, 2018 ( in millions) : Optical Communications Commercial Lasers Total Balance as of beginning of period $ 5.9 $ 5.5 $ 11.4 Foreign currency translation adjustment 0.4 — 0.4 Balance as of end of period $ 6.3 $ 5.5 $ 11.8 Impairment of Goodwill We review goodwill for impairment during the fourth quarter of each fiscal year or more frequently if events or circumstances indicate that an impairment loss may have occurred. In the fourth quarter of fiscal 2017 , we completed the annual impairment test of goodwill, which indicated there was no goodwill impairment. During the three and nine months ended March 31, 2018 , there have been no events or circumstances that have required us to perform an interim assessment of goodwill for impairment. Acquired Developed Technology and Other Intangibles The following tables present details of our acquired developed technology and other intangibles ( in millions ): As of March 31, 2018 Gross Carrying Amount Accumulated Amortization Net Acquired developed technology $ 105.9 $ (97.8 ) $ 8.1 Other 9.4 (9.4 ) — Total Intangibles $ 115.3 $ (107.2 ) $ 8.1 As of July 1, 2017 Gross Carrying Amount Accumulated Amortization Net Acquired developed technology $ 105.5 $ (95.4 ) $ 10.1 Other 9.4 (9.4 ) — Total Intangibles $ 114.9 $ (104.8 ) $ 10.1 The amounts in the table above include cumulative foreign currency translation adjustments, reflecting movement in the currencies of the underlying intangibles. During the three and nine months ended March 31, 2018 , we recorded $0.8 million and $2.4 million , respectively, of amortization related to acquired developed technology. During the three and nine months ended April 1, 2017, we recorded $1.8 million and $5.4 million , respectively, of amortization related to acquired developed technology and other intangibles. The following table presents details of amortization for the periods presented (in millions ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Cost of sales $ 0.8 $ 1.7 $ 2.4 $ 5.1 Operating expenses — 0.1 — 0.3 Total $ 0.8 $ 1.8 $ 2.4 $ 5.4 Based on the carrying amount of acquired developed technology and other intangibles as of March 31, 2018 , and assuming no future impairment of the underlying assets, the estimated future amortization is as follows (in millions): Fiscal Years Remainder of 2018 $ 0.8 2019 3.1 2020 3.0 2021 0.5 2022 0.5 Thereafter 0.2 Total amortization $ 8.1

Restructuring and Related Charg

Restructuring and Related Charges	9 Months Ended
	Mar. 31, 2018
Restructuring and Related Activities [Abstract]
Restructuring and Related Charges	Note 13. Restructuring and Related Charges The following table summarizes the activity of restructuring and related charges during the three and nine months ended March 31, 2018 and April 1, 2017 ( in millions ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Balance as of beginning of period $ 0.4 $ 6.0 $ 3.8 $ 5.7 Charges 0.1 3.1 3.8 10.0 Payments (0.5 ) (3.8 ) (7.6 ) (10.4 ) Balance as of end of period $ — $ 5.3 $ — $ 5.3 During the three and nine months ended March 31, 2018 , we recorded $0.1 million and $3.8 million , respectively, in restructuring and related charges in the condensed consolidated statements of operations, primarily attributable to costs to vacate facilities, temporary labor and employee related benefits, as well as costs for materials used in set up and production activities. We incurred no additional costs related to severance for the same periods. During the three and nine months ended April 1, 2017, we recorded $3.1 million and $10.0 million , respectively, in restructuring and related charges in the condensed consolidated statements of operations. Of the $3.1 million and $10.0 million charges recorded during the three and nine months ended April 1, 2017, $0.4 million and $2.2 million , respectively, was related to severance, retention, lease termination costs, and employee benefits; and $2.7 million and $7.8 million , respectively, was related to other restructuring related charges which include relocation costs, temporary labor and employee related benefits, as well as costs for materials used in set up and production activities.

Income Taxes

Income Taxes	9 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Note 14. Income Taxes Our tax provision for interim periods is determined using an estimate of our annual effective tax rate, adjusted for discrete items, if any, that arise during the period. Each quarter, we update our estimate of the annual effective tax rate, and if the estimated annual effective tax rate changes, we make a cumulative adjustment in such period. Our quarterly tax provision, and estimate of our annual effective tax rate, is subject to variation due to several factors, including variability in pre-tax income (or loss), the mix of jurisdictions to which such income relates, changes in how we do business, and tax law developments. Our estimated effective tax rate for the year differs from the U.S. statutory rate primarily due to the benefit of foreign earnings of our subsidiaries being taxed at rates lower than the U.S. statutory rate. We recorded an immaterial tax benefit and a tax benefit of $112.9 million for the three and nine months ended March 31, 2018, respectively. Our tax benefit for the three months ended March 31, 2018 was less than $0.1 million primarily due to a benefit from foreign rate differential, excess windfall benefit from our stock-based compensation tax deduction, offset by the discrete impact of the non-deductible unrealized loss from the embedded derivatives for the Series A Preferred Stock. Our tax benefit for the nine months ended March 31, 2018 was primarily due to the release of our U.S. federal and certain state valuation allowances. The benefit of this valuation allowance release was partially offset by a non-cash deferred expense associated with the change in the U.S. statutory rate as a result of the Tax Act (discussed further below) which was enacted during our second quarter of fiscal 2018. We recorded a tax provision of $11.6 million and $15.4 million for the three and nine months ended April 1, 2017, respectively. Our tax provision for the three and nine months ended April 1, 2017 was primarily due to the discrete impact of the non-deductible unrealized loss from the embedded derivatives for the Series A Preferred Stock and the 2024 Notes, non-deductible stock-based compensation and partially offset by foreign rate differential, R&D tax credits and the utilization of U.S. deferred tax assets that were subject to a full valuation allowance. We assess our ability to realize the deferred tax assets on a quarterly basis and establish a valuation allowance if the deferred tax assets are not more-likely-than-not to be realized. We weigh all available positive and negative evidence, including our earnings history and results of recent operations, reversals of deferred tax liabilities, projected future taxable income, and tax planning strategies. As of each reporting date, we consider new evidence, both positive and negative, that could affect our view of the future realization of deferred tax assets. As of December 30, 2017, we determined that there is sufficient positive evidence to conclude that it is more-likely-than-not that the deferred tax assets are realizable. We, therefore, released the valuation allowance for the U.S. federal and certain states and recognized a tax benefit of $207 million as a discrete item for the fiscal second quarter of 2018. Due to the weight of negative evidence, we continue to maintain a full valuation allowance on the California deferred tax assets. On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act makes broad and complex changes to the U.S. tax code that will affect our fiscal year ending June 30, 2018, including, but not limited to, (1) a reduction in the U.S. federal corporate tax rate; (2) a transition tax on certain deferred income of foreign subsidiaries that, if the taxpayer so elects, is payable over eight years; and (3) bonus depreciation that allows full expensing of qualified property. The Tax Act reduces the federal corporate tax rate to 21 percent in the fiscal year ending June 30, 2018. Section 15 of the Internal Revenue Code stipulates that our fiscal year ending June 30, 2018 will have a blended corporate tax rate of 28 percent, which is based on the applicable tax rates before and after the Tax Act and the number of days in each period. The Tax Act also establishes new tax laws that will affect our fiscal year ending June 30, 2019, including, but not limited to, (1) reduction of the U.S. federal corporate tax rate; (2) elimination of the corporate alternative minimum tax; (3) the creation of the base erosion anti-abuse tax (“BEAT”), a new minimum tax on taxable income adjusted for certain base erosion payments; (4) a general elimination of U.S. federal income taxes on dividends from foreign subsidiaries; (5) a new provision designed to currently tax certain global intangible low-taxed income (“GILTI”) of controlled foreign corporations, which allows for the possibility of using foreign tax credits (“FTCs”) and a deduction of up to 50 percent to reduce this income tax liability (subject to some limitations); (6) a new limitation on deductible interest expense; (7) the repeal of the domestic production activity deduction; (8) limitations on the deductibility of certain executive compensation; (9) limitations on the use of FTCs to reduce the U.S. income tax liability; and (10) limitations on net operating losses generated in the taxable years beginning after December 31, 2017, to 80 percent of taxable income. The SEC staff issued SAB 118, which provides guidance on accounting for the tax effects of the Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the accounting under ASC 740. In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Tax Act for which the accounting under ASC 740 is complete. To the extent that a company’s accounting for certain income tax effects of the Tax Act is incomplete but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act. In connection with our initial analysis of the impact of the Tax Act, we have recorded a provisional tax expense of $83 million as a result of the rate decrease, which was accounted for as discrete item in the tax provision for the second quarter of fiscal year 2018. We are required to recognize the effect of this rate change on our deferred tax assets and liabilities and deferred tax asset valuation allowances in the period the tax rate change was enacted. The reduction in the U.S. federal statutory rate is expected to positively impact our federal cash tax liability. However, the ultimate impact is subject to the effect of other complex provisions in the Tax Act (including the BEAT and GILTI), which we are currently reviewing, and it is possible that any impact of BEAT and GILTI could significantly reduce the benefit of the reduction in the U.S. federal statutory rate. Due to the uncertain practical and technical application of many of these provisions, it is currently not possible to reliably estimate whether BEAT and GILTI will apply and, if so, how it would impact us. We will continue to analyze the Tax Act to assess the full effects on our financial results for the June 30, 2018 fiscal year-end. Our accounting for the following elements of the Tax Act is incomplete. However, we were able to make reasonable estimates of certain effects and, therefore, recorded provisional adjustments as follows: • The Tax Act reduces the corporate tax rate to 21 percent, effective January 1, 2018. For certain of our deferred tax assets and deferred tax liabilities, we have recorded a provisional net decrease of deferred tax assets by $83 million , with a corresponding net adjustment to deferred income tax expense of $83 million , which was accounted for as discrete item in the tax provision for the second quarter of fiscal year 2018. While we are able to make a reasonable estimate of the impact of the reduction in corporate rate, it may be affected by other analyses related to the Tax Act, including, but not limited to, our calculation of deemed repatriation of deferred foreign income and the state tax effect of adjustments made to federal temporary differences. • The Deemed Repatriation Transition Tax (“Transition Tax”) is a tax on previously untaxed accumulated and current earnings and profits (“E&P”) of certain of our foreign subsidiaries. To determine the amount of the Transition Tax, we must determine, in addition to other factors, the amount of post-1986 E&P of the relevant subsidiaries, as well as the amount of non-U.S. income taxes paid on such earnings. We are continuing to gather additional information to more precisely compute the amount of the Transition Tax. • Due to complexity of the new GILTI tax rules, we are continuing to evaluate this provision of the Tax Act and the application of ASC 740. Under U.S. GAAP, we are allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred (the “period cost method”) or (2) factoring such amounts into a company’s measurement of its deferred taxes (the “deferred method”). Our selection of an accounting policy with respect to the new GILTI tax rules will depend, in part, on analyzing our global income to determine whether we expect to have future U.S. inclusions in taxable income related to GILTI and, if so, what the impact is expected to be. Whether we expect to have future U.S. inclusions in taxable income related to GILTI depends not only on our current structure and estimated future results of global operations but also on our intent and ability to modify our structure and/or our business; as such, we are not yet able to reasonably estimate the effect of this provision of the Tax Act. Therefore, we have not made any adjustments related to potential GILTI tax in our financial statements and have not made a policy decision regarding whether to record deferred taxes on GILTI. As of March 31, 2018, we had $10.2 million of unrecognized tax benefits, which, if recognized, would affect the effective tax rate. We are subject to examination of income tax returns by various domestic and foreign tax authorities. The timing of resolutions and closures of tax audits is highly unpredictable. Given the uncertainty, it is reasonably possible that certain tax audits may be concluded within the next 12 months that could materially impact the balance of our gross unrecognized tax benefits. An estimate of the range of increase or decrease that could occur in the next twelve months cannot be made. However, the estimated impact to tax expense and net income from the resolution and closure of tax exams is not expected to be significant within the next 12 months.

Stock-Based Compensation and St

Stock-Based Compensation and Stock Plans	9 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation and Stock Plans	Note 15. Stock-Based Compensation and Stock Plans Description of Lumentum Stock-Based Benefit Plans Stock Option Plans On June 23, 2015, we adopted, and the board of directors of JDSU approved, the 2015 Equity Incentive Plan (the “2015 Plan”) under which 8.5 million shares of our common stock were authorized for issuance, which was ratified by our board of directors in August 2015. In connection with our Separation from JDSU on July 31, 2015, outstanding JDSU equity-based awards held by service providers continuing in service after the Separation were converted into equity-based awards under the 2015 Plan reducing the number of shares remaining available for grant under the 2015 Plan. Immediately following our Separation from JDSU, 2.1 million shares of our common stock were reserved pursuant to outstanding equity-based awards under the 2015 Plan that were converted from JDSU equity-based awards. On November 4, 2016, our stockholders approved an amendment to increase the number of shares that may be issued under the 2015 Plan by 3.0 million shares, and certain other material terms of the 2015 Plan. As of March 31, 2018 , we had 2.1 million shares subject to stock options, restricted stock units, restricted stock awards, and performance stock units issued and outstanding under the 2015 Plan. Restricted stock units, restricted stock awards, and performance stock units are performance-based, time-based or a combination of both and are expected to vest over one to four years. The fair value of these grants is based on the closing market price of our common stock on the date of award. The exercise price for stock options is equal to the fair value of the underlying stock at the date of grant. We issue new shares of common stock upon exercise of stock options. Options generally become exercisable over a three -year or four -year period and, if not exercised, expire from five to ten years after the date of grant. As of March 31, 2018 , 5.7 million shares of common stock under the 2015 Plan were available for grant. Employee Stock Purchase Plan On June 23, 2015, we adopted, and the board of directors of JDSU approved, the 2015 Employee Stock Purchase Plan (the “2015 Purchase Plan”) under which 3.0 million shares of our common stock were authorized for issuance, which was ratified by our board of directors in August 2015. The 2015 Purchase Plan provides eligible employees with the opportunity to acquire an ownership interest in the Company through periodic payroll deductions and provides a 15% purchase price discount as well as a six -month look-back period. The 2015 Purchase Plan is structured as a qualified employee stock purchase plan under Section 423 of the Internal Revenue Code of 1986. However, the 2015 Purchase Plan is not intended to be a qualified pension, profit sharing or stock bonus plan under Section 401(a) of the Internal Revenue Code of 1986 and is not subject to the provisions of the Employee Retirement Income Security Act of 1974. The 2015 Purchase Plan will terminate upon the date on which all shares available for issuance have been sold. Of the 3.0 million shares authorized under the 2015 Purchase Plan, 2.4 million shares remained available for issuance as of March 31, 2018 . Restricted Stock Units Restricted stock units (“RSUs”) under the 2015 Plan are grants of shares of our common stock valued at fair value based on the closing price of our common stock on the date of grant. RSUs result in a payment to a holder if any performance goals or other vesting criteria are achieved or the awards otherwise vest. Generally, our RSUs have service conditions and are expected to vest over one to four years. Restricted Stock Awards Restricted stock awards (“RSAs”) under the 2015 Plan are grants of shares of our common stock that are subject to various restrictions, including restrictions on transferability and forfeiture provisions. RSAs are expected to vest over one to four years, and the shares acquired may not be transferred by the holder until the vesting conditions (if any) are satisfied. Performance Stock Units Performance stock units (“PSUs”) under the 2015 Plan are grants of shares of our common stock that vest upon the achievement of certain performance and service conditions. We begin recognizing compensation expense when we conclude that it is probable that the performance conditions will be achieved. We reassess the probability of vesting at each reporting period and adjust our compensation cost based on this probability assessment. Our PSUs are subject to risk of forfeiture until performance and service conditions are satisfied and generally vest over three years. During the nine months ended March 31, 2018, we granted 116,788 PSUs to senior members of our management team and recorded $1.6 million expense related to these grants based on the revenue performance condition that is expected to be achieved. During the three months ended March 31, 2018, we recorded $0.4 million expense related to these grants. Stock-Based Compensation The impact on our results of operations of recording stock-based compensation by function for the three and nine months ended March 31, 2018 and April 1, 2017 was as follows (in millions) : Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Cost of sales $ 2.4 $ 1.9 $ 9.5 $ 6.0 Research and development 3.6 3.0 10.5 8.8 Selling, general and administrative 5.0 3.2 15.1 10.2 $ 11.0 $ 8.1 $ 35.1 $ 25.0 Approximately $2.1 million and $1.8 million of stock-based compensation was capitalized to inventory as of March 31, 2018 and July 1, 2017 , respectively. Stock Option and Stock Award Activity We did not grant any stock options during the three and nine months ended March 31, 2018 and April 1, 2017 . During the nine months ended March 31, 2018 , there were 41,727 options exercised. No options were exercised during the three months ended March 31, 2018. As of March 31, 2018 , 3,057 options were outstanding under the 2015 Plan. During the nine months ended March 31, 2018 , the total intrinsic value of options exercised by our employees was $0.8 million . The total intrinsic value of options exercised by our employees during the three and nine months ended April 1, 2017 was $1.0 million and $4.6 million , respectively. In connection with these exercises, the tax benefit realized during the three and nine months ended April 1, 2017 was $2.3 million and $5.2 million , respectively. During the three and nine months ended March 31, 2018 , due to adoption of ASU 2016-09, all excess tax benefits and deficiencies were recognized in the income tax provision in the condensed consolidated statements of operations, rather than in additional paid-in-capital in the condensed consolidated balance sheets. Refer to “ Note 1. Description of Business and Summary of Significant Accounting Policies ” in the Notes to Unaudited Condensed Consolidated Financial Statements for further discussion on the impact of the adoption of ASU 2016-09. The following table summarizes our awards activity for the nine months ended March 31, 2018 (in millions, except per share amounts) : Restricted Stock Units Restricted Stock Awards Performance Stock Units Number of Shares Weighted-Average Grant Date Fair Value per Share Number of Shares Weighted-Average Grant Date Fair Value per Share Number of Shares Weighted-Average Grant Date Fair Value per Share Unvested balance as of beginning of period 1.9 $ 28.04 0.3 $ 32.51 — $ — Granted 1.0 53.35 — — 0.1 52.00 Vested (0.9 ) 26.60 (0.1 ) 32.51 — — Canceled (0.2 ) 38.23 — — — — Unvested balance as of end of period 1.8 $ 43.08 0.2 $ 32.51 0.1 $ 52.00 As of March 31, 2018 , $72.5 million of stock-based compensation cost related to awards granted to our employees remains to be amortized. That cost is expected to be recognized over an estimated amortization period of 1.8 years . A summary of awards available for grant is as follows (in millions) : Awards Available for Grant Balance as of beginning of period 6.6 Granted (1.1 ) Canceled 0.2 Balance as of end of period 5.7 Employee Stock Purchase Plan Activity The 2015 Purchase Plan expense for the three and nine months ended March 31, 2018 was $0.8 million and $2.4 million , respectively. The expense related to the 2015 Purchase Plan is recorded on a straight-line basis over the relevant subscription period. During the nine months ended March 31, 2018 , there were 93,044 shares issued to employees through the 2015 Purchase Plan in one offering period from May 16, 2017 to November 15, 2017. The 2015 Purchase Plan expense for the three and nine months ended April 1, 2017 was $0.7 million and $2.0 million , respectively. During the nine months ended April 1, 2017, there were 188,864 shares issued to employees through the 2015 Purchase Plan in one offering period from May 16, 2016 to November 15, 2016. We estimate the fair value of the 2015 Purchase Plan shares on the date of grant using the Black-Scholes option-pricing model. The assumptions used to estimate the fair value of the 2015 Purchase Plan shares to be issued during the nine months ended March 31, 2018 and April 1, 2017 were as follows: March 31, 2018 April 1, 2017 Expected term (years) 0.5 0.5 Expected volatility 49.9 % 46.0 % Risk-free interest rate 1.42 % 0.62 % Dividend yield — % — %

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 16. Commitments and Contingencies Operating Leases We lease certain real and personal property from unrelated third parties under non-cancellable operating leases that expire at various dates through fiscal 2026. Certain leases require us to pay property taxes, insurance and routine maintenance, and include escalation clauses. As of March 31, 2018 , the future minimum annual lease payments under non-cancellable operating leases were as follows ( in millions ): Fiscal Years Remainder of 2018 $ 2.9 2019 11.9 2020 9.0 2021 5.2 2022 3.5 Thereafter 4.3 Total minimum operating lease payments $ 36.8 During the three and nine months ended March 31, 2018 , rental expense relating to building and equipment was $2.8 million and $9.2 million , respectively. During the three and nine months ended April 1, 2017 , rental expense relating to building and equipment was $2.6 million and $7.0 million , respectively. Capital Lease As of March 31, 2018 , equipment acquired under a capital lease agreement was $15.6 million . Our capital lease asset is included in property, plant and equipment, net in our condensed consolidated balance sheets as of March 31, 2018 . Amortization expense on this capital lease asset is recorded as depreciation expense and is included in cost of sales in our condensed consolidated statements of operations for the three and nine months ended March 31, 2018 . Our capital lease obligation is recorded at the lesser of the estimated fair market value of the leased property or the net present value of the aggregate future minimum lease payments and is included in other current liabilities and other non-current liabilities in our condensed consolidated balance sheets as of March 31, 2018 . Refer to “ Note 6. Balance Sheet Details ” for capital lease obligation amounts in other current liabilities and other non-current liabilities. Interest on these obligations is included in interest expense in our condensed consolidated statements of operations. As of March 31, 2018 the future minimum annual lease payments under our capital lease were as follows ( in millions ): Fiscal Years Remainder of 2018 $ 4.7 2019 7.5 2020 0.4 Total minimum capital lease payments $ 12.6 Less: amount representing interest $ (0.3 ) Present value of capital lease obligation $ 12.3 Acquisition Contingencies We incurred liabilities in the amount of $3.6 million in connection with the fiscal 2017 acquisition. The amount of $2.7 million is payable 36 months following the acquisition date contingent upon meeting certain production targets. We retained $0.9 million of the purchase price as security for any potential liabilities of the seller under the representations, warranties and indemnifications included in the purchase agreement, which amount less any amounts required to cover seller’s indemnification obligations is payable to the seller at the 15 month anniversary of the close date. 0.25% Convertible Senior Notes due 2024 The future interest and principal payments related to the 2024 Notes are as follows as of March 31, 2018 : Fiscal Years 2019 $ 1.1 2020 1.1 2021 1.1 2022 1.1 Thereafter 451.7 Total 2024 Notes payments $ 456.1 Purchase Obligations Purchase obligations of $187.1 million as of March 31, 2018 , represent legally-binding commitments to purchase inventory and other commitments made in the normal course of business to meet operational requirements. Although open purchase orders are considered enforceable and legally binding, the terms generally allow the option to cancel, reschedule and adjust the requirements based on our business needs prior to the delivery of goods or performance of services. Obligations to purchase inventory and other commitments are generally expected to be fulfilled within one year. We depend on a limited number of contract manufacturers, subcontractors and suppliers for raw materials, packages and standard components. We generally purchase these single or limited source products through standard purchase orders or one-year supply agreements and have no significant long-term guaranteed supply agreements with such vendors. While we seek to maintain a sufficient safety stock of such products and maintain on-going communications with our suppliers to guard against interruptions or cessation of supply, our business and results of operations could be adversely affected by a stoppage or delay of supply, substitution of more expensive or less reliable products, receipt of defective parts or contaminated materials, increases in the price of such supplies, or our inability to obtain reduced pricing from our suppliers in response to competitive pressures. Product Warranties We provide reserves for the estimated costs of product warranties at the time revenue is recognized. We typically offer a twelve month warranty for most of our products. However, in some instances depending upon the product, product component or application of our products by the end customer, our warranties can vary and generally range from six months to five years. We estimate the costs of our warranty obligations on an annualized basis based on our historical experience of known product failure rates, use of materials to repair or replace defective products and service delivery costs incurred in correcting product failures. In addition, from time to time, specific warranty accruals may be made if unforeseen technical problems arise with specific products. We assess the adequacy of our recorded warranty liabilities and adjust the amounts as necessary. The following table presents the changes in our warranty reserve during the three and nine months ended March 31, 2018 and April 1, 2017 ( in millions ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Balance as of beginning of period $ 9.9 $ 8.7 $ 9.7 $ 2.8 Provision for warranty (1) 2.0 0.6 4.9 9.3 Utilization of reserve (4.9 ) (1.2 ) (7.6 ) (4.0 ) Balance as of end of period $ 7.0 $ 8.1 $ 7.0 $ 8.1 (1) This does not include a settlement payment of $5.1 million received from a vendor for a quality issue during the three months ended March 31, 2018 . Environmental Liabilities Our research and development (“R&D”), manufacturing and distribution operations involve the use of hazardous substances and are regulated under international, federal, state and local laws governing health and safety and the environment. We apply strict standards for protection of the environment and occupational health and safety to sites inside and outside the United States, even if not subject to regulations imposed by foreign governments. We believe that our properties and operations at our facilities comply in all material respects with applicable environmental laws and occupational health and safety laws. However, the risk of environmental liabilities cannot be completely eliminated and there can be no assurance that the application of environmental and health and safety laws will not require us to incur significant expenditures. We are also regulated under a number of international, federal, state and local laws regarding recycling, product packaging and product content requirements. The environmental, product content/disposal and recycling laws are gradually becoming more stringent and may cause us to incur significant expenditures in the future. In connection with the Separation, we agreed to indemnify Viavi for any liability associated with contamination from past operations at all properties transferred to us from Viavi, to the extent the resulting issues primarily related to our business. Legal Proceedings We are subject to a variety of claims and suits that arise from time to time in the ordinary course of our business. While management currently believes that resolving claims against us, individually or in the aggregate, will not have a material adverse impact on our financial position, results of operations or statements of cash flows, these matters are subject to inherent uncertainties and management’s view of these matters may change in the future. We accrue for loss contingencies when it is both probable that we will incur the loss and when we can reasonably estimate the amount of the loss or range of loss. Indemnifications In the normal course of business, we enter into agreements that contain a variety of representations and warranties and provide for general indemnification. Exposure under these agreements is unknown because claims may be made against us in the future and we may record charges in the future as a result of these indemnification obligations. As of March 31, 2018 , we did not have any material indemnification claims that were probable or reasonably possible.

Operating Segments and Geograph

Operating Segments and Geographic Information	9 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Operating Segments and Geographic Information	Note 17. Operating Segments and Geographic Information Our chief executive officer is our Chief Operating Decision Maker (“CODM”). The CODM allocates resources to the segments based on their business prospects, competitive factors, net revenue and gross margin. We have two operating segments, Optical Communications, which we refer to as OpComms, and Commercial Lasers, which we refer to as Lasers. Our OpComms products address the following markets: telecommunications (“Telecom”), data communications (“Datacom”), and consumer and industrial (“Consumer and Industrial”). The two operating segments were primarily determined based on how the CODM views and evaluates our operations. Operating results are regularly reviewed by the CODM to make decisions about resources to be allocated to the segments and to assess their performance. Other factors, including market separation and customer specific applications, go-to-market channels, products and manufacturing, are considered in determining the formation of these operating segments. We do not allocate research and development, sales and marketing, or general and administrative expenses to our segments because management does not include the information in its measurement of the performance of the operating segments. In addition, we do not allocate amortization and impairment of acquisition-related intangible assets, stock-based compensation and certain other charges impacting the gross margin of each segment because management does not include this information in its measurement of the performance of the operating segments. Information on reportable segments utilized by our CODM is as follows ( in millions) : Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Net revenue: OpComms $ 246.3 $ 216.1 $ 814.3 $ 671.0 Lasers 52.5 39.7 132.3 107.9 Net revenue $ 298.8 $ 255.8 $ 946.6 $ 778.9 Gross profit: OpComms 83.1 71.5 317.1 229.2 Lasers 25.4 16.4 55.9 44.8 Total segment gross profit 108.5 87.9 373.0 274.0 Unallocated corporate items: Stock-based compensation (2.4 ) (1.9 ) (9.5 ) (6.0 ) Amortization of intangibles (0.8 ) (1.7 ) (2.4 ) (5.1 ) Other charges (1) (8.3 ) (2.2 ) (24.5 ) (12.1 ) Gross profit $ 97.0 $ 82.1 $ 336.6 $ 250.8 (1) The increase in “Other charges” of unallocated corporate items during the three months ended March 31, 2018 compared to the three months ended April 1, 2017 , primarily relates to set-up costs of our facility in Thailand, including costs of transferring product lines to Thailand. The increase in “Other charges” of unallocated corporate items during the nine months ended March 31, 2018 compared to the nine months ended April 1, 2017 , primarily relates to set-up costs of our facility in Thailand, including costs of transferring product lines to Thailand, as well as inventory write-downs due to canceled programs not allocated to the segments. The table below discloses the percentage of our total net revenue attributable to each of our two reportable segments. In addition, it discloses the percentage of our total net revenue attributable to our product offerings which serve the Telecom, Datacom and Consumer and Industrial markets which accounted for 10% or more of our total net revenue: Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 OpComms: 82.4 % 84.5 % 86.0 % 86.1 % Telecom 41.0 % 64.5 % 36.3 % 63.0 % Datacom 12.1 % 15.2 % 12.2 % 19.4 % Consumer and Industrial 29.3 % 4.8 % 37.5 % 3.7 % Lasers 17.6 % 15.5 % 14.0 % 13.9 % We operate in three geographic regions: Americas, Asia-Pacific, and EMEA (Europe, Middle East, and Africa). Net revenue is assigned to the geographic region and country where our product is initially shipped. For example, certain customers may request shipment of our product to a contract manufacturer in one country, which may differ from the location of their end customers. The following table presents net revenue by the three geographic regions we operate in and net revenue from countries that represented 10% of our total net revenue (in millions, except percentage data) : Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Net revenue: Americas: United States $ 26.8 9.0 % $ 34.7 13.6 % $ 86.3 9.1 % $ 106.2 13.6 % Mexico 41.7 14.0 70.0 27.4 97.1 10.3 158.5 20.3 Other Americas 1.5 0.5 1.5 0.6 5.7 0.6 7.4 1.0 Total Americas $ 70.0 23.5 % $ 106.2 41.6 % $ 189.1 20.0 % $ 272.1 34.9 % Asia-Pacific: Hong Kong $ 38.7 13.0 % $ 47.2 18.5 % $ 133.3 14.1 % $ 181.2 23.3 % China 47.3 15.8 8.7 3.4 66.8 7.1 28.3 3.6 Japan 34.1 11.4 25.9 10.1 157.6 16.6 78.5 10.1 South Korea 28.8 9.6 2.4 0.9 126.3 13.3 3.5 0.4 Other Asia-Pacific 56.6 18.9 35.3 13.8 199.3 21.1 133.0 17.1 Total Asia-Pacific $ 205.5 68.7 % $ 119.5 46.7 % $ 683.3 72.2 % $ 424.5 54.5 % EMEA $ 23.3 7.8 % $ 30.1 11.8 % $ 74.2 7.8 % $ 82.3 10.6 % Total net revenue $ 298.8 $ 255.8 $ 946.6 $ 778.9 During the three and nine months ended March 31, 2018 and April 1, 2017 , net revenue generated from a single end customer which represented 10% or greater of total net revenue is summarized as follows: Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Customer A 25.0 % * 33.0 % * Customer B 12.0 % 12.0 % 11.0 % 18.0 % Customer C 13.0 % 27.0 % * 20.0 % Customer D * * * 12.0 % *Represents less than 10% of total net revenue Long-lived assets, namely net property, plant and equipment were identified based on the physical location of the assets in the corresponding geographic areas (in millions) : As of March 31, 2018 July 1, 2017 Property, Plant and Equipment, net United States $ 97.4 $ 88.2 China 76.9 82.5 Thailand 92.9 85.3 Other countries 34.6 17.5 Total long-lived assets $ 301.8 $ 273.5 We purchase a substantial portion of our inventory from contract manufacturers and vendors located primarily in Taiwan, Thailand, and China. During the three and nine months ended March 31, 2018 and April 1, 2017 , net inventory purchased from a single contract manufacturer which represented 10% or greater of total net purchases is summarized as follows: Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Vendor A 48.0 % 50.0 % 42.0 % 52.0 % Vendor B 19.0 % 26.0 % 19.0 % 26.0 % Vendor C 18.0 % * 23.0 % * Vendor D * 16.0 % * 14.0 % *Represents less than 10% of total net purchases

Description of Business and S24

Description of Business and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The preparation of the condensed consolidated financial statements in accordance with U.S. generally accepted accounting principles (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported in our condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and various other assumptions believed to be reasonable. Although these estimates are based on management’s best knowledge of current events and actions that may impact the Company in the future, actual results may be different from the estimates. Our critical accounting policies are those that affect our financial statements materially and involve difficult, subjective or complex judgments by management. Those policies are revenue recognition, inventory valuation, derivative liability valuation, long-lived asset valuation, warranty and accounting for income taxes.
Fiscal Years	Fiscal Years We utilize a 52-53 week fiscal year ending on the Saturday closest to June 30th. Our fiscal 2018 is a 52-week year ending on June 30, 2018 . Our fiscal 2017 was a 52-week year and ended on July 1, 2017 .
Principles of Consolidation	Principles of Consolidation These interim unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All inter-company transactions and balances have been eliminated in consolidation.
Recently Issued Accounting Pronouncements	Accounting Policies The accompanying interim unaudited condensed consolidated financial statements and accompanying related notes should be read in conjunction with the audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the fiscal year ended July 1, 2017 . Effective July 2, 2017, we adopted Accounting Standards Update (“ASU”) 2016-09, Stock Compensation ASU 718 - Improvements to Employee Share-Based Payment Accounting . As a result of the adoption, in the first quarter of fiscal year 2018, we recorded on a modified retrospective basis a $2.6 million cumulative-effect adjustment to retained earnings for the recognition of excess tax benefits generated by the settlement of share-based awards in prior periods. We elected to account for forfeitures of equity awards when they occur. The change was applied on a modified retrospective basis with a cumulative-effect adjustment of approximately $0.2 million to retained earnings in the fiscal first quarter of 2018. All excess tax benefits and deficiencies are recognized in the income tax provision in the condensed consolidated statements of operations prospectively, rather than in additional paid-in-capital in the condensed consolidated balance sheets. In addition, the standard eliminates the requirement to defer recognition of excess tax benefits until they are realized through a reduction to income taxes payable. We present excess tax benefits as an operating activity in the condensed consolidated statements of cash flows on a prospective basis. In January 2017, the Financial Accounting Standards Board (“FASB”) issued ASU 2017-01, Business Combinations (Topic 805) , which clarifies the definition of a business. For accounting and financial reporting purposes, businesses are generally comprised of three elements; inputs, processes, and outputs. Integrated sets of assets and activities capable of providing these three elements may not always be considered a business, and the lack of one of the three elements does not always disqualify the set from being a business. The issuance of ASU 2017-01 provides a clarifying screen to determine when a set of assets and activities is not a business. Primarily, the screen requires that when substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets, the set is not a business. The amendments contained in ASU 2017-01 are effective for annual periods beginning after December 15, 2017, including interim periods within those periods. The accounting standard update will be effective for us beginning in the first quarter of fiscal 2019 and should be applied prospectively. We do not believe the implementation of ASU 2017-01 will have a material impact on our condensed consolidated financial statements. In January 2017, FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Accounting for Goodwill Impairment . ASU 2017-04 removes the requirement to perform a hypothetical purchase price allocation to measure goodwill impairment. A goodwill impairment charge will be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The amendments contained in ASU 2017-04 are effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted, which should be applied prospectively. We plan to adopt the accounting standard update in our first quarter of fiscal 2019. We do not believe the implementation of ASU 2017-04 will have a material impact on our condensed consolidated financial statements. In August 2016, FASB issued ASU 2016-15, S tatement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments , which clarifies how companies present and classify certain cash receipts and cash payments in the statement of cash flows. The amendments contained in ASU 2016-15 are effective for interim and annual periods beginning after December 15, 2017. The accounting standard update will be effective for us in the first quarter of fiscal 2019 and will be applied prospectively. If we elect to settle the principal amounts of our 2024 Notes (refer to “ Note 10. Convertible Senior Notes ”) in cash, the payment will be bifurcated between (i) cash outflows for operating activities of $137.6 million for the portion related to accreted interest attributable to debt discount, and (ii) financing activities for the remainder of $312.4 million . In February 2016, FASB issued ASU 2016-02, Leases. The new guidance generally requires an entity to recognize on its balance sheet operating and financing lease liabilities and corresponding right-of-use assets. The new guidance contained in ASU 2016-02 is effective for annual periods beginning after December 15, 2018, including interim periods within those periods, with early adoption permitted. The standard is effective for us in our first quarter of fiscal 2020 and should be applied prospectively. Based on our current lease portfolio, we estimate the value of leased assets and liabilities that may be recognized will be material. We are continuing to evaluate the impact of ASU 2016-02 and is subject to change. In May 2014, FASB issued ASU 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which amended the existing accounting standards for revenue recognition. ASU 2014-09 establishes principles for recognizing revenue upon the transfer of promised goods or services to customers, in an amount that reflects the consideration expected to be received in exchange for those goods or services. The new standard requires that reporting companies disclose the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. On July 9, 2015, FASB agreed to delay the effective date by one year, and accordingly, the new standard is effective for us at the beginning of the first quarter of fiscal 2019. The guidance to ASU 2014-09 permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (modified retrospective method). We selected the modified retrospective method. We do not anticipate that the adoption of ASU 2014-09 will have a material impact on our consolidated financial statements including the potential impact of the additional disclosure requirement, primarily because we will continue to recognize most revenue at a point-in-time when control transfers. This is similar to the current revenue recognition model. We currently recognize revenue when all four revenue recognition criteria have been met: (i) persuasive evidence of an arrangement exists, (ii) the product has been delivered or the service has been rendered, (iii) the price is fixed or determinable and (iv) collection is reasonably assured. Revenue from product sales is recorded when all of the foregoing conditions are met and risk of loss and title passes to the customer. Our products typically include a warranty and the estimated cost of product warranty claims, based on historical experience, is recorded at the time the sale is recognized. Sales to customers are generally not subject to price protection or return rights. The majority of our sales are made to OEMs, distributors, resellers and end-users. We are implementing changes to our accounting policies, internal controls, and disclosures to support the new standard; however, these changes will not be material.
Short-term Investments	We use the specific-identification method to determine any realized gains or losses from the sale of our short-term investments classified as available-for-sale.
Fair Value Measurements	We determine fair value based on the fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value assumes that the transaction to sell the asset or transfer the liability occurs in the principal or most advantageous market for the asset or liability and establishes that the fair value of an asset or liability shall be determined based on the assumptions that market participants would use in pricing the asset or liability. The classification of a financial asset or liability within the hierarchy is based upon the lowest level input that is significant to the fair value measurement. The fair value hierarchy prioritizes the inputs into three levels that may be used to measure fair value: Level 1: Inputs are unadjusted quoted prices in active markets for identical assets or liabilities. Level 2: Inputs are quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. Level 3: Inputs are unobservable inputs based on our assumptions. The fair value of the Company’s Level 1 financial instruments, such as money market funds, which are traded in active markets, is based on quoted market prices for identical instruments. The fair value of the Company’s Level 2 fixed income securities is obtained from an independent pricing service, which may use quoted market prices for identical or comparable instruments or model driven valuations using observable market data or inputs corroborated by observable market data. Our marketable securities are held by custodians who obtain investment prices from a third-party pricing provider that incorporates standard inputs in various asset price models. The Company’s procedures include controls to ensure that appropriate fair values are recorded, including comparing the fair values obtained from the Company’s pricing service against fair values obtained from another independent source. We estimate the fair value of the embedded derivative for the Series A Preferred Stock using the binomial lattice model. The lattice model requires the various assumptions to be made to determine the fair value of the embedded derivatives. These assumptions represent Level 3 inputs. Refer to “ Note 11. Derivative Liability ” in the Notes to Unaudited Condensed Consolidated Financial Statements. In February 2017, we completed the acquisition of a privately held company to enhance our manufacturing and vertical integration capabilities for a total purchase consideration of $8.7 million . We estimated the fair value of our Level 3 contingent consideration related to this acquisition at the present value of the expected contingent payments, determined using a probabilistic approach. We are required to reassess the fair value of contingent payments on a periodic basis. During the three months ended April 1, 2017 , we estimated the likelihood of meeting the production targets at 90 percent . There was no change in the fair value of our contingent consideration during the three and nine months ended March 31, 2018 . The fair value of such contingent consideration is recorded in accrued liabilities on the condensed consolidated balance sheet as of March 31, 2018 . This contingent consideration will result in a cash payment of $3.0 million , if and when the production targets are achieved, which we expect to occur within 36 months following the acquisition date. Our pension assets consist of multiple institutional funds (“pension funds”) of which the fair values are based on the quoted prices of the underlying funds. Pension funds are classified as Level 2 assets since such funds are not directly traded in active markets. We periodically review our intangible and other long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Determination of recoverability is based on the lowest level of identifiable estimated undiscounted cash flows resulting from use of the asset and its eventual disposition. If not recoverable, an impairment loss would be calculated based on the excess of the carrying amount over the fair value. Management utilizes various valuation methods, including an income approach, a market approach and a cost approach, to estimate the fair value of intangible and other long-lived assets. During the annual impairment testing performed in fiscal 2017, all our intangible and other long-lived assets passed Step 1. No impairment charges were recorded in fiscal 2017 or during the three and nine months ended March 31, 2018 . Refer to “ Note 12. Goodwill and Other Intangible Assets ”.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted net (loss) income per share	The following table sets forth the computation of basic and diluted net income (loss) attributable to common stockholders per share ( in millions, except per share data ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Basic Earnings per Common Share Net income (loss) $ 2.7 $ (56.0 ) $ 214.6 $ (47.6 ) Less: Cumulative dividends on Series A Preferred Stock (0.2 ) (0.2 ) (0.7 ) (0.6 ) Less: Earnings allocated to Series A Preferred Stock (0.1 ) — (4.9 ) — Net income (loss) attributable to common stockholders - basic $ 2.4 $ (56.2 ) $ 209.00 $ (48.2 ) Weighted average common shares outstanding including Series A Preferred Stock 63.9 62.5 63.6 61.9 Less: Weighted average Series A Preferred Stock (1.5 ) (1.5 ) (1.5 ) (1.5 ) Basic weighted average common shares outstanding 62.4 61.0 62.1 60.4 Net income (loss) per share attributable to common stockholders - basic $ 0.04 $ (0.92 ) $ 3.37 $ (0.80 ) Diluted Earnings per Common Share Net income (loss) attributable to common stockholders - diluted $ 2.4 $ (56.2 ) $ 209.0 $ (48.2 ) Weighted average common shares outstanding for basic earnings per common share 62.4 61.0 62.1 60.4 Effect of dilutive securities from stock-based benefit plans 0.9 — 1.1 — Effect of diluted securities from Series A Preferred Stock — — — — Diluted weighted average common shares outstanding 63.3 61.0 63.2 60.4 Net income (loss) per share attributable to common stockholders - diluted $ 0.04 $ (0.92 ) $ 3.31 $ (0.80 )

Accumulated Other Comprehensi26

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Mar. 31, 2018
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Schedule of accumulated other comprehensive income	As of March 31, 2018 and July 1, 2017 , balances for the components of accumulated other comprehensive income (loss) were as follows ( in millions ): Foreign currency translation adjustments, net of tax Defined benefit obligation, net of tax Unrealized gain (loss) on available-for-sale securities, net of tax Total Beginning balance as of July 1, 2017 $ 10.5 $ (3.1 ) $ — $ 7.4 Other comprehensive income (loss) 1.9 — (2.0 ) (0.1 ) Ending balance as of March 31, 2018 $ 12.4 $ (3.1 ) $ (2.0 ) $ 7.3

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	9 Months Ended
	Mar. 31, 2018
Balance Sheet and Other Details
Schedule of components of Inventories	The components of inventories were as follows ( in millions ): March 31, 2018 July 1, 2017 Finished goods $ 93.2 $ 71.7 Work in process 30.5 49.4 Raw materials and purchased parts 20.5 24.1 Inventories $ 144.2 $ 145.2
Schedule of components of Prepayments and other current assets	The components of prepayments and other current assets were as follows ( in millions ): March 31, 2018 July 1, 2017 Capitalized manufacturing overhead $ 23.9 $ 30.1 Prepayments 14.8 12.3 Advances to contract manufacturers 15.0 10.5 Other current assets 9.3 10.6 Prepayments and other current assets $ 63.0 $ 63.5
Schedule of components of Property, plant and equipment	The components of property, plant and equipment, net were as follows ( in millions ): March 31, 2018 July 1, 2017 Land $ 10.6 $ 10.6 Buildings and improvement 49.3 37.3 Machinery and equipment (1) 543.2 461.1 Computer equipment and software 37.3 31.2 Furniture and fixtures 4.9 4.6 Leasehold improvements 30.1 30.5 Construction in progress 63.2 84.6 738.6 659.9 Less: Accumulated depreciation (436.8 ) (386.4 ) Property, plant and equipment, net $ 301.8 $ 273.5 (1) In the first quarter of fiscal 2018, we started leasing equipment from a vendor and have accounted for the transaction as a capital lease. Included in the table above is our capital lease asset of $11.9 million , net of depreciation expense of $3.7 million as of March 31, 2018 .
Schedule of components of Other current liabilities	The components of other current liabilities were as follows (in millions) : March 31, 2018 July 1, 2017 Warranty accrual (1) $ 7.0 $ 9.7 Restructuring accrual and related charges (2) — 3.8 Deferred revenue and customer deposits 2.5 6.9 Capital lease obligation (3) 9.2 — Other current liabilities 2.3 1.5 Other current liabilities $ 21.0 $ 21.9 (1) Refer to “ Note 16. Commitments and Contingencies ” in the Notes to Unaudited Condensed Consolidated Financial Statements. (2) Refer to “ Note 13. Restructuring and Related Charges ” in the Notes to Unaudited Condensed Consolidated Financial Statements. (3) As of March 31, 2018 , an amount of $2.3 million related to a capital lease was recorded in accounts payable on the condensed consolidated balance sheet. Refer to “ Note 16. Commitments and Contingencies ” in the Notes to Unaudited Condensed Consolidated Financial Statements.
Schedule of components of Other non-current liabilities	The components of other non-current liabilities were as follows ( in millions ): March 31, 2018 July 1, 2017 Asset retirement obligation $ 2.7 $ 2.5 Pension and related accrual 3.2 3.9 Deferred rent 3.1 3.3 Unrecognized tax benefit 10.2 10.5 Capital lease obligation (1) 0.8 — Other non-current liabilities 4.2 4.8 Other non-current liabilities $ 24.2 $ 25.0 (1) Refer to “ Note 16. Commitments and Contingencies ” in the Notes to Unaudited Condensed Consolidated Financial Statements.

Cash, Cash Equivalents, and S28

Cash, Cash Equivalents, and Short-term Investments (Tables)	9 Months Ended
	Mar. 31, 2018
Cash and Cash Equivalents [Abstract]
Schedule of Cash and Cash Equivalents	The following table summarizes our cash, cash equivalents, and short-term investments by category for the periods presented ( in millions ): Amortized Gross Gross Fair Value March 31, 2018: Cash $ 82.6 $ — $ — $ 82.6 Cash equivalents: Commercial paper 29.1 — — 29.1 Corporate debt securities 26.0 — — 26.0 Money market funds 2.5 — — 2.5 Municipal bonds 1.5 — — 1.5 Foreign government bonds 2.0 2.0 U.S. Treasury 26.7 — — 26.7 Asset-backed securities 6.4 — — 6.4 Total cash and cash equivalents $ 176.8 $ — $ — $ 176.8 Short-term investments: Certificates of deposit $ 32.0 $ — $ — $ 32.0 Commercial paper 35.1 — — 35.1 Asset-backed securities 114.3 — (0.3 ) 114.0 Corporate debt securities 317.6 0.1 (1.8 ) 315.9 Municipal bonds 6.2 — — 6.2 Mortgage-backed securities 4.8 — — 4.8 Foreign government bonds 8.0 — — 8.0 Total short-term investments $ 518.0 $ 0.1 $ (2.1 ) $ 516.0 July 1, 2017: Cash $ 201.3 $ — $ — $ 201.3 Cash equivalents: Certificates of deposit 52.1 — — 52.1 Commercial paper 14.7 — — 14.7 Money market funds 4.8 — — 4.8 Total cash and cash equivalents $ 272.9 $ — $ — $ 272.9 Short-term investments: Certificates of deposit $ 202.1 $ — $ — $ 202.1 Asset-backed securities 26.1 — — 26.1 Corporate debt securities 46.4 — — 46.4 Municipal bonds 4.9 — — 4.9 Foreign government bonds 1.0 — — 1.0 U.S. Treasury 1.9 — — 1.9 Total short-term investments $ 282.4 $ — $ — $ 282.4
Schedule of Short-term Investments	The following table summarizes our cash, cash equivalents, and short-term investments by category for the periods presented ( in millions ): Amortized Gross Gross Fair Value March 31, 2018: Cash $ 82.6 $ — $ — $ 82.6 Cash equivalents: Commercial paper 29.1 — — 29.1 Corporate debt securities 26.0 — — 26.0 Money market funds 2.5 — — 2.5 Municipal bonds 1.5 — — 1.5 Foreign government bonds 2.0 2.0 U.S. Treasury 26.7 — — 26.7 Asset-backed securities 6.4 — — 6.4 Total cash and cash equivalents $ 176.8 $ — $ — $ 176.8 Short-term investments: Certificates of deposit $ 32.0 $ — $ — $ 32.0 Commercial paper 35.1 — — 35.1 Asset-backed securities 114.3 — (0.3 ) 114.0 Corporate debt securities 317.6 0.1 (1.8 ) 315.9 Municipal bonds 6.2 — — 6.2 Mortgage-backed securities 4.8 — — 4.8 Foreign government bonds 8.0 — — 8.0 Total short-term investments $ 518.0 $ 0.1 $ (2.1 ) $ 516.0 July 1, 2017: Cash $ 201.3 $ — $ — $ 201.3 Cash equivalents: Certificates of deposit 52.1 — — 52.1 Commercial paper 14.7 — — 14.7 Money market funds 4.8 — — 4.8 Total cash and cash equivalents $ 272.9 $ — $ — $ 272.9 Short-term investments: Certificates of deposit $ 202.1 $ — $ — $ 202.1 Asset-backed securities 26.1 — — 26.1 Corporate debt securities 46.4 — — 46.4 Municipal bonds 4.9 — — 4.9 Foreign government bonds 1.0 — — 1.0 U.S. Treasury 1.9 — — 1.9 Total short-term investments $ 282.4 $ — $ — $ 282.4
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	The following table summarizes unrealized losses on our cash equivalents and short-term investments by category and length of time the investment has been in a continuous unrealized loss position as of the periods presented (in millions) : Less than 12 months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses March 31, 2018: Certificates of deposit $ 25.4 $ — $ — $ — $ 25.4 $ — Commercial paper 39.7 — — — 39.7 — Asset-backed securities 112.9 (0.3 ) — — 112.9 (0.3 ) Corporate debt securities 291.8 (1.8 ) — — 291.8 (1.8 ) Municipal bonds 6.2 — — — 6.2 — Mortgage-backed securities 4.5 — — — 4.5 — U.S. Treasury 3.0 — — — 3.0 — Foreign government bonds 8.8 — — — 8.8 — Total $ 492.3 $ (2.1 ) $ — $ — $ 492.3 $ (2.1 ) July 1, 2017: Asset-backed securities $ 21.5 $ — $ — $ — $ 21.5 $ — Corporate debt securities 29.8 — — — 29.8 — Municipal bonds 2.9 — — — 2.9 — Foreign government bonds 1.0 — — — 1.0 — U.S. Treasury 1.9 — — — 1.9 — Total $ 57.1 $ — $ — $ — $ 57.1 $ —
Investments Classified by Contractual Maturity Date	The following table classifies our investments in debt securities by contractual maturities ( in millions ): As of March 31, 2018 Amortized Cost Fair Value Due in 1 year $ 252.1 $ 251.5 Due in 1 year through 5 years 252.7 251.3 Due in 5 years through 10 years 7.2 7.2 Due after 10 years 6.0 6.0 $ 518.0 $ 516.0

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	Financial assets and liabilities measured at fair value on a recurring basis are summarized below ( in millions ): Level 1 Level 2 Level 3 Total March 31, 2018: Assets: Cash equivalents: Commercial paper $ — $ 29.1 $ — $ 29.1 Corporate debt securities — 26.0 — 26.0 Money market funds 2.5 — — 2.5 Municipal bonds — 1.5 — 1.5 Foreign government bonds — 2.0 — 2.0 U.S. Treasury 26.7 — — 26.7 Asset-backed securities — 6.4 — 6.4 Short-term investments: Certificates of deposit — 32.0 — 32.0 Commercial paper — 35.1 — 35.1 Asset-backed securities — 114.0 — 114.0 Corporate debt securities — 315.9 — 315.9 Municipal bonds — 6.2 — 6.2 Mortgage-backed securities — 4.8 — 4.8 Foreign government bonds — 8.0 — 8.0 Total assets $ 29.2 $ 581.0 $ — $ 610.2 Other accrued liabilities: Derivative liability $ — $ — $ 60.2 $ 60.2 Acquisition contingencies — — 2.7 2.7 Total other accrued liabilities $ — $ — $ 62.9 $ 62.9 Level 1 Level 2 Level 3 Total July 1, 2017: Assets: Cash equivalents: Certificates of deposit $ — $ 52.1 $ — $ 52.1 Commercial paper — 14.7 — 14.7 Money market funds 4.8 — — 4.8 Short-term investments: Certificates of deposit — 202.1 — 202.1 Asset-backed securities — 26.1 — 26.1 Corporate debt securities — 46.4 — 46.4 Municipal bonds — 4.9 — 4.9 Foreign government bonds — 1.0 — 1.0 U.S. Treasury 1.9 — — 1.9 Total assets $ 6.7 $ 347.3 $ — $ 354.0 Other accrued liabilities: Derivative liability $ — $ — $ 51.6 $ 51.6 Acquisition contingencies — — 2.7 2.7 Total other accrued liabilities $ — $ — $ 54.3 $ 54.3

Convertible Senior Notes (Table

Convertible Senior Notes (Tables)	9 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Convertible Debt	As of March 31, 2018 , the 2024 Notes consisted of the following ( in millions ): Liability component: March 31, 2018 July 1, 2017 Principal $ 450.0 $ 450.0 Unamortized debt discount (120.1 ) (132.5 ) Net carrying amount of the liability component $ 329.9 $ 317.5
Interest Expense on Convertible Debt	The following table sets forth interest expense information related to the 2024 Notes for the three and nine months ended March 31, 2018 : March 31, 2018 (in millions, except percentages) Three Months Ended Nine Months Ended Contractual interest expense $ 0.3 $ 0.9 Amortization of the debt discount 4.2 12.4 Total interest expense $ 4.5 $ 13.3 Effective interest rate on the liability component 5.4 % 5.4 %

Derivative Liability (Tables)

Derivative Liability (Tables)	9 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Reconciliation of fair value of embedded derivative for Series A preferred stock	The following table provides a reconciliation of the fair value of the embedded derivative for the 2024 Notes for the three and nine months ended March 31, 2018 and April 1, 2017 ( in millions ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Balance as of beginning of period $ — $ — $ — $ — Fair value of the embedded derivative for the 2024 Notes at issuance — (129.9 ) — (129.9 ) Unrealized loss on the 2024 Notes derivative liability — (38.7 ) — (38.7 ) Balance as of end of period $ — $ (168.6 ) $ — $ (168.6 ) The following table provides a reconciliation of the fair value of the embedded derivative for the Series A Preferred Stock for the three and nine months ended March 31, 2018 and April 1, 2017 ( in millions ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Balance as of beginning of period $ (39.5 ) $ (28.2 ) $ (51.6 ) $ (10.3 ) Unrealized loss on the Series A Preferred Stock derivative liability (20.7 ) (17.9 ) (8.6 ) (35.8 ) Balance as of end of period $ (60.2 ) $ (46.1 ) $ (60.2 ) $ (46.1 )
Schedule of fair value assumptions for derivative liability	The following table summarizes the assumptions used to determine the fair value of the embedded derivative for Series A Preferred Stock: March 31, 2018 July 1, 2017 Stock price $ 63.80 $ 57.05 Conversion price $ 24.63 $ 24.63 Expected term (years) 2.37 3.11 Expected annual volatility 50.0 % 47.5 % Risk-free rate 2.31 % 1.57 % Preferred yield 8.32 % 7.56 %

Goodwill and Other Intangible32

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes in goodwill	The following table presents the changes in goodwill by our reportable segments during the nine months ended March 31, 2018 ( in millions) : Optical Communications Commercial Lasers Total Balance as of beginning of period $ 5.9 $ 5.5 $ 11.4 Foreign currency translation adjustment 0.4 — 0.4 Balance as of end of period $ 6.3 $ 5.5 $ 11.8
Acquired developed technology and other intangibles	The following tables present details of our acquired developed technology and other intangibles ( in millions ): As of March 31, 2018 Gross Carrying Amount Accumulated Amortization Net Acquired developed technology $ 105.9 $ (97.8 ) $ 8.1 Other 9.4 (9.4 ) — Total Intangibles $ 115.3 $ (107.2 ) $ 8.1 As of July 1, 2017 Gross Carrying Amount Accumulated Amortization Net Acquired developed technology $ 105.5 $ (95.4 ) $ 10.1 Other 9.4 (9.4 ) — Total Intangibles $ 114.9 $ (104.8 ) $ 10.1
Intangible assets amortization expense	The following table presents details of amortization for the periods presented (in millions ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Cost of sales $ 0.8 $ 1.7 $ 2.4 $ 5.1 Operating expenses — 0.1 — 0.3 Total $ 0.8 $ 1.8 $ 2.4 $ 5.4
Future amortization expense	Based on the carrying amount of acquired developed technology and other intangibles as of March 31, 2018 , and assuming no future impairment of the underlying assets, the estimated future amortization is as follows (in millions): Fiscal Years Remainder of 2018 $ 0.8 2019 3.1 2020 3.0 2021 0.5 2022 0.5 Thereafter 0.2 Total amortization $ 8.1

Restructuring and Related Cha33

Restructuring and Related Charges (Tables)	9 Months Ended
	Mar. 31, 2018
Restructuring and Related Activities [Abstract]
Schedule of various restructuring plans	The following table summarizes the activity of restructuring and related charges during the three and nine months ended March 31, 2018 and April 1, 2017 ( in millions ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Balance as of beginning of period $ 0.4 $ 6.0 $ 3.8 $ 5.7 Charges 0.1 3.1 3.8 10.0 Payments (0.5 ) (3.8 ) (7.6 ) (10.4 ) Balance as of end of period $ — $ 5.3 $ — $ 5.3

Stock-Based Compensation and 34

Stock-Based Compensation and Stock Plans (Tables)	9 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of the impact on the entity's results of operations of recording stock-based compensation by function	The impact on our results of operations of recording stock-based compensation by function for the three and nine months ended March 31, 2018 and April 1, 2017 was as follows (in millions) : Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Cost of sales $ 2.4 $ 1.9 $ 9.5 $ 6.0 Research and development 3.6 3.0 10.5 8.8 Selling, general and administrative 5.0 3.2 15.1 10.2 $ 11.0 $ 8.1 $ 35.1 $ 25.0
Schedule of stock options activities	The following table summarizes our awards activity for the nine months ended March 31, 2018 (in millions, except per share amounts) : Restricted Stock Units Restricted Stock Awards Performance Stock Units Number of Shares Weighted-Average Grant Date Fair Value per Share Number of Shares Weighted-Average Grant Date Fair Value per Share Number of Shares Weighted-Average Grant Date Fair Value per Share Unvested balance as of beginning of period 1.9 $ 28.04 0.3 $ 32.51 — $ — Granted 1.0 53.35 — — 0.1 52.00 Vested (0.9 ) 26.60 (0.1 ) 32.51 — — Canceled (0.2 ) 38.23 — — — — Unvested balance as of end of period 1.8 $ 43.08 0.2 $ 32.51 0.1 $ 52.00
Schedule of awards available for grant	A summary of awards available for grant is as follows (in millions) : Awards Available for Grant Balance as of beginning of period 6.6 Granted (1.1 ) Canceled 0.2 Balance as of end of period 5.7
Schedule of ESPP valuation assumptions	We estimate the fair value of the 2015 Purchase Plan shares on the date of grant using the Black-Scholes option-pricing model. The assumptions used to estimate the fair value of the 2015 Purchase Plan shares to be issued during the nine months ended March 31, 2018 and April 1, 2017 were as follows: March 31, 2018 April 1, 2017 Expected term (years) 0.5 0.5 Expected volatility 49.9 % 46.0 % Risk-free interest rate 1.42 % 0.62 % Dividend yield — % — %

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum annual lease payments under non-cancellable operating leases	As of March 31, 2018 , the future minimum annual lease payments under non-cancellable operating leases were as follows ( in millions ): Fiscal Years Remainder of 2018 $ 2.9 2019 11.9 2020 9.0 2021 5.2 2022 3.5 Thereafter 4.3 Total minimum operating lease payments $ 36.8
Schedule of future minimum lease payments for capital leases	As of March 31, 2018 the future minimum annual lease payments under our capital lease were as follows ( in millions ): Fiscal Years Remainder of 2018 $ 4.7 2019 7.5 2020 0.4 Total minimum capital lease payments $ 12.6 Less: amount representing interest $ (0.3 ) Present value of capital lease obligation $ 12.3
Schedule of future interest and principal payments related to 2024 Notes	The future interest and principal payments related to the 2024 Notes are as follows as of March 31, 2018 : Fiscal Years 2019 $ 1.1 2020 1.1 2021 1.1 2022 1.1 Thereafter 451.7 Total 2024 Notes payments $ 456.1
Schedule of changes in the entity's warranty reserve	The following table presents the changes in our warranty reserve during the three and nine months ended March 31, 2018 and April 1, 2017 ( in millions ): Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Balance as of beginning of period $ 9.9 $ 8.7 $ 9.7 $ 2.8 Provision for warranty (1) 2.0 0.6 4.9 9.3 Utilization of reserve (4.9 ) (1.2 ) (7.6 ) (4.0 ) Balance as of end of period $ 7.0 $ 8.1 $ 7.0 $ 8.1 (1) This does not include a settlement payment of $5.1 million received from a vendor for a quality issue during the three months ended March 31, 2018 .

Operating Segments and Geogra36

Operating Segments and Geographic Information (Tables)	9 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Schedule of information on reportable segments	Information on reportable segments utilized by our CODM is as follows ( in millions) : Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Net revenue: OpComms $ 246.3 $ 216.1 $ 814.3 $ 671.0 Lasers 52.5 39.7 132.3 107.9 Net revenue $ 298.8 $ 255.8 $ 946.6 $ 778.9 Gross profit: OpComms 83.1 71.5 317.1 229.2 Lasers 25.4 16.4 55.9 44.8 Total segment gross profit 108.5 87.9 373.0 274.0 Unallocated corporate items: Stock-based compensation (2.4 ) (1.9 ) (9.5 ) (6.0 ) Amortization of intangibles (0.8 ) (1.7 ) (2.4 ) (5.1 ) Other charges (1) (8.3 ) (2.2 ) (24.5 ) (12.1 ) Gross profit $ 97.0 $ 82.1 $ 336.6 $ 250.8 (1) The increase in “Other charges” of unallocated corporate items during the three months ended March 31, 2018 compared to the three months ended April 1, 2017 , primarily relates to set-up costs of our facility in Thailand, including costs of transferring product lines to Thailand. The increase in “Other charges” of unallocated corporate items during the nine months ended March 31, 2018 compared to the nine months ended April 1, 2017 , primarily relates to set-up costs of our facility in Thailand, including costs of transferring product lines to Thailand, as well as inventory write-downs due to canceled programs not allocated to the segments.
Schedule of concentration risks	During the three and nine months ended March 31, 2018 and April 1, 2017 , net revenue generated from a single end customer which represented 10% or greater of total net revenue is summarized as follows: Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Customer A 25.0 % * 33.0 % * Customer B 12.0 % 12.0 % 11.0 % 18.0 % Customer C 13.0 % 27.0 % * 20.0 % Customer D * * * 12.0 % *Represents less than 10% of total net revenue During the three and nine months ended March 31, 2018 and April 1, 2017 , net inventory purchased from a single contract manufacturer which represented 10% or greater of total net purchases is summarized as follows: Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Vendor A 48.0 % 50.0 % 42.0 % 52.0 % Vendor B 19.0 % 26.0 % 19.0 % 26.0 % Vendor C 18.0 % * 23.0 % * Vendor D * 16.0 % * 14.0 % *Represents less than 10% of total net purchases The table below discloses the percentage of our total net revenue attributable to each of our two reportable segments. In addition, it discloses the percentage of our total net revenue attributable to our product offerings which serve the Telecom, Datacom and Consumer and Industrial markets which accounted for 10% or more of our total net revenue: Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 OpComms: 82.4 % 84.5 % 86.0 % 86.1 % Telecom 41.0 % 64.5 % 36.3 % 63.0 % Datacom 12.1 % 15.2 % 12.2 % 19.4 % Consumer and Industrial 29.3 % 4.8 % 37.5 % 3.7 % Lasers 17.6 % 15.5 % 14.0 % 13.9 %
Schedule of revenue by geographical region	The following table presents net revenue by the three geographic regions we operate in and net revenue from countries that represented 10% of our total net revenue (in millions, except percentage data) : Three Months Ended Nine Months Ended March 31, 2018 April 1, 2017 March 31, 2018 April 1, 2017 Net revenue: Americas: United States $ 26.8 9.0 % $ 34.7 13.6 % $ 86.3 9.1 % $ 106.2 13.6 % Mexico 41.7 14.0 70.0 27.4 97.1 10.3 158.5 20.3 Other Americas 1.5 0.5 1.5 0.6 5.7 0.6 7.4 1.0 Total Americas $ 70.0 23.5 % $ 106.2 41.6 % $ 189.1 20.0 % $ 272.1 34.9 % Asia-Pacific: Hong Kong $ 38.7 13.0 % $ 47.2 18.5 % $ 133.3 14.1 % $ 181.2 23.3 % China 47.3 15.8 8.7 3.4 66.8 7.1 28.3 3.6 Japan 34.1 11.4 25.9 10.1 157.6 16.6 78.5 10.1 South Korea 28.8 9.6 2.4 0.9 126.3 13.3 3.5 0.4 Other Asia-Pacific 56.6 18.9 35.3 13.8 199.3 21.1 133.0 17.1 Total Asia-Pacific $ 205.5 68.7 % $ 119.5 46.7 % $ 683.3 72.2 % $ 424.5 54.5 % EMEA $ 23.3 7.8 % $ 30.1 11.8 % $ 74.2 7.8 % $ 82.3 10.6 % Total net revenue $ 298.8 $ 255.8 $ 946.6 $ 778.9
Schedule of long-lived assets by geographical region	Long-lived assets, namely net property, plant and equipment were identified based on the physical location of the assets in the corresponding geographic areas (in millions) : As of March 31, 2018 July 1, 2017 Property, Plant and Equipment, net United States $ 97.4 $ 88.2 China 76.9 82.5 Thailand 92.9 85.3 Other countries 34.6 17.5 Total long-lived assets $ 301.8 $ 273.5

Description of Business and S37

Description of Business and Summary of Significant Accounting Policies - Merger Agreement (Details)	Mar. 11, 2018USD ($)$ / shares	Mar. 31, 2018USD ($)
Oclaro, Inc.
Acquisitions
Percentage of interest owned by Oclaro shareholders of combined company	16.00%
Oclaro, Inc.
Acquisitions
Exchange for consideration, cash paid for each share of Oclaro common stock (usd per share) | $ / shares	$ 5.60
Exchange for consideration, shares paid paid for each share of Oclaro common stock (in shares)	0.0636
Total purchase consideration	$ 1,800,000,000
Cash paid in total transaction consideration	416,000,000
New debt incurred in total transaction consideration	550,000,000
Equity issued in total transaction consideration	859,000,000
Senior secured term loan facility		$ 550,000,000
Provision for additional senior secured term loans		$ 250,000,000
Oclaro, Inc. | Lumentum
Acquisitions
Termination fee if terms of Merger Agreement not met	$ 80,000,000

Description of Business and S38

Description of Business and Summary of Significant Accounting Policies - Accounting Policies (Details) - Retained Earnings $ in Millions	Jul. 01, 2017USD ($)
Accounting Standards Update 2016-09, Excess Tax Benefit Component
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative impact of new guidance, increase to retained earnings	$ 2.6
Accounting Standards Update 2016-09, Forfeiture Rate
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative impact of new guidance, increase to retained earnings	$ 0.2

Recently Issued Accounting Pr39

Recently Issued Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 29, 2018	Mar. 31, 2018	Apr. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by (used in) operating activities		$ 209.9	$ 71.9
Net cash provided by (used in) financing activities		$ 1.9	$ 454.7
Accounting Standards Update 2016-15 | Forecast
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by (used in) operating activities	$ 137.6
Net cash provided by (used in) financing activities	$ 312.4

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017	Jul. 01, 2017	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion price (usd per share)	$ 24.63		$ 24.63		$ 24.63
Basic Earnings per Common Share
Net income (loss)	$ 2,700,000	$ (56,000,000)	$ 214,600,000	$ (47,600,000)
Less: Cumulative dividends on Series A Preferred Stock	(200,000)	(200,000)	(700,000)	(600,000)
Less: Earnings allocated to Series A Preferred Stock	(100,000)	0	(4,900,000)	0
Net income (loss) attributable to common stockholders	$ 2,400,000	$ (56,200,000)	$ 209,000,000	$ (48,200,000)
Weighted average common shares outstanding including participating securities (in shares)	63.9	62.5	63.6	61.9
Less: Weighted average participating securities (in shares)	(1.5)	(1.5)	(1.5)	(1.5)
Basic weighted average common shares outstanding (in shares)	62.4	61	62.1	60.4
Basic (usd per share)	$ 0.04	$ (0.92)	$ 3.37	$ (0.80)
Diluted Earnings per Common Share
Net income (loss) attributable to common stockholders - diluted	$ 2,400,000	$ (56,200,000)	$ 209,000,000	$ (48,200,000)
Basic weighted average common shares outstanding (in shares)	62.4	61	62.1	60.4
Effect of dilutive securities from stock-based benefit plans (in shares)	0.9	0	1.1	0
Effect of diluted securities from Series A Preferred Stock (in shares)	0	0	0	0
Diluted shares available to common stockholders (in shares)	63.3	61	63.2	60.4
Diluted (usd per share)	$ 0.04	$ (0.92)	$ 3.31	$ (0.80)
Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from calculation of diluted shares (in shares)	1.5
Convertible Debt | Convertible Senior Notes Due 2024
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt, aggregate principal amount	$ 450,000,000		$ 450,000,000		$ 450,000,000	$ 450,000,000
Debt, stated interest rate						0.25%
Conversion price (usd per share)						$ 60.62

Accumulated Other Comprehensi41

Accumulated Other Comprehensive Income (Loss) (Details) $ in Millions	9 Months Ended
	Mar. 31, 2018USD ($)
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	$ 618.8
Other comprehensive income (loss)	(0.1)
Balance at the end of the period	876.6
Foreign currency translation adjustments, net of tax
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	10.5
Other comprehensive income (loss)	1.9
Balance at the end of the period	12.4
Defined benefit obligation, net of tax
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	(3.1)
Other comprehensive income (loss)	0
Balance at the end of the period	(3.1)
Unrealized gain (loss) on available-for-sale securities, net of tax
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	0
Other comprehensive income (loss)	(2)
Balance at the end of the period	(2)
Total
Changes in accumulated other comprehensive income (loss) by component
Balance at the beginning of the period	7.4
Balance at the end of the period	$ 7.3

Asset Acquisition (Details)

Asset Acquisition (Details) $ in Millions	Mar. 30, 2018USD ($)
Asset Acquisition [Abstract]
Required cash payment upon completion of certain milestones related to purchase of equipment	$ 5.3

Balance Sheet Details (Details)

Balance Sheet Details (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017	Dec. 30, 2017	Jul. 01, 2017	Dec. 31, 2016	Jul. 02, 2016
Accounts receivable allowance
Accounts receivable allowance	$ 1.8		$ 1.8			$ 1.8
Inventories
Finished goods	93.2		93.2			71.7
Work in process	30.5		30.5			49.4
Raw materials and purchased parts	20.5		20.5			24.1
Inventories	144.2		144.2			145.2
Prepayments and other current assets
Capitalized manufacturing overhead	23.9		23.9			30.1
Prepayments	14.8		14.8			12.3
Advances to contract manufacturers	15		15			10.5
Other current assets	9.3		9.3			10.6
Prepayments and other current assets	63		63			63.5
Other current liabilities
Warranty accrual	7		7			9.7
Restructuring accrual and related charges	0	$ 5.3	0	$ 5.3	$ 0.4	3.8	$ 6	$ 5.7
Deferred revenue and customer deposits	2.5		2.5			6.9
Capital lease obligation	9.2		9.2			0
Other current liabilities	2.3		2.3			1.5
Other current liabilities	21		21			21.9
Property, plant and equipment
Property, plant and equipment, gross	738.6		738.6			659.9
Less: Accumulated depreciation	(436.8)		(436.8)			(386.4)
Property, plant and equipment, net	301.8		301.8			273.5
Depreciation expense	18.4	$ 14.1	53.3	$ 39.1
Other non-current liabilities
Asset retirement obligation	2.7		2.7			2.5
Pension and related accrual	3.2		3.2			3.9
Deferred rent	3.1		3.1			3.3
Unrecognized tax benefit	10.2		10.2			10.5
Capital lease obligation	0.8		0.8			0
Other non-current liabilities	4.2		4.2			4.8
Other non-current liabilities	24.2		24.2			25
Land
Property, plant and equipment
Property, plant and equipment, gross	10.6		10.6			10.6
Buildings and improvement
Property, plant and equipment
Property, plant and equipment, gross	49.3		49.3			37.3
Machinery and equipment
Property, plant and equipment
Property, plant and equipment, gross	543.2		543.2			461.1
Computer equipment and software
Property, plant and equipment
Property, plant and equipment, gross	37.3		37.3			31.2
Furniture and fixtures
Property, plant and equipment
Property, plant and equipment, gross	4.9		4.9			4.6
Leasehold improvements
Property, plant and equipment
Property, plant and equipment, gross	30.1		30.1			30.5
Construction in progress
Property, plant and equipment
Property, plant and equipment, gross	63.2		63.2			$ 84.6
Capital leased assets
Property, plant and equipment
Property, plant and equipment, gross	15.6		15.6
Less: Accumulated depreciation	(3.7)		(3.7)
Property, plant and equipment, net	11.9		11.9
Accounts Payable
Other current liabilities
Capital lease obligation	$ 2.3		$ 2.3

Cash, Cash Equivalents, and S44

Cash, Cash Equivalents, and Short-term Investments - Summary of Cash, Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jul. 01, 2017	Apr. 01, 2017	Jul. 02, 2016
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 176.8	$ 272.9	$ 577.9	$ 157.1
Amortized Cost	518	282.4
Gross Unrealized Gains	0.1	0
Gross Unrealized Losses	(2.1)	0
Fair Value	516	282.4
U.S. Treasury
Cash and Cash Equivalents [Line Items]
Amortized Cost		1.9
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value		1.9
Certificates of deposit
Cash and Cash Equivalents [Line Items]
Amortized Cost	32	202.1
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	32	202.1
Commercial paper
Cash and Cash Equivalents [Line Items]
Amortized Cost	35.1
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	35.1
Asset-backed securities
Cash and Cash Equivalents [Line Items]
Amortized Cost	114.3	26.1
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(0.3)	0
Fair Value	114	26.1
Corporate debt securities
Cash and Cash Equivalents [Line Items]
Amortized Cost	317.6	46.4
Gross Unrealized Gains	0.1	0
Gross Unrealized Losses	(1.8)	0
Fair Value	315.9	46.4
Municipal bonds
Cash and Cash Equivalents [Line Items]
Amortized Cost	6.2	4.9
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	6.2	4.9
Mortgage-backed securities
Cash and Cash Equivalents [Line Items]
Amortized Cost	4.8
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	4.8
Foreign government bonds
Cash and Cash Equivalents [Line Items]
Amortized Cost	8	1
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	8	1
Cash
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	82.6	201.3
Certificates of deposit
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents		52.1
Commercial paper
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	29.1	14.7
Corporate debt securities
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	26
Money market funds
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	2.5	$ 4.8
Municipal bonds
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	1.5
Foreign government bonds
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	2
U.S. Treasury
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	26.7
Asset-backed securities
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 6.4

Cash, Cash Equivalents, and S45

Cash, Cash Equivalents, and Short-term Investments - Summary of Continuous Unrealized Losses (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jul. 01, 2017
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 492.3	$ 57.1
12 Months or Greater	0	0
Total	492.3	57.1
Unrealized Losses
Less than 12 months	(2.1)	0
12 Months or Greater	0	0
Total	(2.1)	0
Certificates of deposit
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	25.4
12 Months or Greater	0
Total	25.4
Unrealized Losses
Less than 12 months	0
12 Months or Greater	0
Total	0
Commercial paper
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	39.7
12 Months or Greater	0
Total	39.7
Unrealized Losses
Less than 12 months	0
12 Months or Greater	0
Total	0
Asset-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	112.9	21.5
12 Months or Greater	0	0
Total	112.9	21.5
Unrealized Losses
Less than 12 months	(0.3)	0
12 Months or Greater	0	0
Total	(0.3)	0
Corporate debt securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	291.8	29.8
12 Months or Greater	0	0
Total	291.8	29.8
Unrealized Losses
Less than 12 months	(1.8)	0
12 Months or Greater	0	0
Total	(1.8)	0
Municipal bonds
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	6.2	2.9
12 Months or Greater	0	0
Total	6.2	2.9
Unrealized Losses
Less than 12 months	0	0
12 Months or Greater	0	0
Total	0	0
Mortgage-backed securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	4.5
12 Months or Greater	0
Total	4.5
Unrealized Losses
Less than 12 months	0
12 Months or Greater	0
Total	0
Foreign government bonds
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	8.8	1
12 Months or Greater	0	0
Total	8.8	1
Unrealized Losses
Less than 12 months	0	0
12 Months or Greater	0	0
Total	0	0
U.S. Treasury
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	3	1.9
12 Months or Greater	0	0
Total	3	1.9
Unrealized Losses
Less than 12 months	0	0
12 Months or Greater	0	0
Total	$ 0	$ 0

Cash, Cash Equivalents, and S46

Cash, Cash Equivalents, and Short-term Investments - Investments in Debt Securities by Contractual Maturities (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jul. 01, 2017
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis [Abstract]
Due in 1 year	$ 252.1
Due in 1 year through 5 years	252.7
Due in 5 years through 10 years	7.2
Due after 10 years	6
Total debt securities, Amortized Cost	518
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Due in 1 year	251.5
Due in 1 year through 5 years	251.3
Due in 5 years through 10 years	7.2
Due after 10 years	6
Total debt securities, Fair Value	$ 516	$ 282.4

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - Private Company Acquisition - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Feb. 28, 2017	Apr. 01, 2017	Mar. 31, 2018
Acquisitions
Total purchase consideration	$ 8.7
Estimated likelihood of achieving production targets		90.00%
Contingent consideration, cash payment that could result if production targets achieved			$ 3

Fair Value Measurements - Measu

Fair Value Measurements - Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jul. 01, 2017
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	$ 492.3	$ 57.1
Certificates of deposit
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	25.4
Commercial paper
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	39.7
Asset-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	112.9	21.5
Corporate debt securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	291.8	29.8
Municipal bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	6.2	2.9
Mortgage-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	4.5
Foreign government bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	8.8	1
U.S. Treasury
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	3	1.9
Recurring basis
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments		354
Total assets	610.2
Other accrued liabilities:
Derivative liability	60.2	51.6
Acquisition contingencies	2.7	2.7
Total other accrued liabilities	62.9	54.3
Recurring basis | Certificates of deposit
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	32	202.1
Recurring basis | Commercial paper
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	35.1
Recurring basis | Asset-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	114	26.1
Recurring basis | Corporate debt securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	315.9	46.4
Recurring basis | Municipal bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	6.2	4.9
Recurring basis | Mortgage-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	4.8
Recurring basis | Foreign government bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	8	1
Recurring basis | U.S. Treasury
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments		1.9
Recurring basis | Certificates of deposit
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents		52.1
Recurring basis | Commercial paper
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	29.1	14.7
Recurring basis | Corporate debt securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	26
Recurring basis | Money market funds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	2.5	4.8
Recurring basis | Municipal bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	1.5
Recurring basis | Foreign government bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	2
Recurring basis | U.S. Treasury
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	26.7
Recurring basis | Asset-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	6.4
Recurring basis | Level 1
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments		6.7
Total assets	29.2
Other accrued liabilities:
Derivative liability	0	0
Acquisition contingencies	0	0
Total other accrued liabilities	0	0
Recurring basis | Level 1 | Certificates of deposit
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0	0
Recurring basis | Level 1 | Commercial paper
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0
Recurring basis | Level 1 | Asset-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0	0
Recurring basis | Level 1 | Corporate debt securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0	0
Recurring basis | Level 1 | Municipal bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0	0
Recurring basis | Level 1 | Mortgage-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0
Recurring basis | Level 1 | Foreign government bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0	0
Recurring basis | Level 1 | U.S. Treasury
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments		1.9
Recurring basis | Level 1 | Certificates of deposit
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents		0
Recurring basis | Level 1 | Commercial paper
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0	0
Recurring basis | Level 1 | Corporate debt securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0
Recurring basis | Level 1 | Money market funds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	2.5	4.8
Recurring basis | Level 1 | Municipal bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0
Recurring basis | Level 1 | Foreign government bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0
Recurring basis | Level 1 | U.S. Treasury
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	26.7
Recurring basis | Level 1 | Asset-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0
Recurring basis | Level 2
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments		347.3
Total assets	581
Other accrued liabilities:
Derivative liability	0	0
Acquisition contingencies	0	0
Total other accrued liabilities	0	0
Recurring basis | Level 2 | Certificates of deposit
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	32	202.1
Recurring basis | Level 2 | Commercial paper
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	35.1
Recurring basis | Level 2 | Asset-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	114	26.1
Recurring basis | Level 2 | Corporate debt securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	315.9	46.4
Recurring basis | Level 2 | Municipal bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	6.2	4.9
Recurring basis | Level 2 | Mortgage-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	4.8
Recurring basis | Level 2 | Foreign government bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	8	1
Recurring basis | Level 2 | U.S. Treasury
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments		0
Recurring basis | Level 2 | Certificates of deposit
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents		52.1
Recurring basis | Level 2 | Commercial paper
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	29.1	14.7
Recurring basis | Level 2 | Corporate debt securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	26
Recurring basis | Level 2 | Money market funds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0	0
Recurring basis | Level 2 | Municipal bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	1.5
Recurring basis | Level 2 | Foreign government bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	2
Recurring basis | Level 2 | U.S. Treasury
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0
Recurring basis | Level 2 | Asset-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	6.4
Recurring basis | Level 3
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments		0
Total assets	0
Other accrued liabilities:
Derivative liability	60.2	51.6
Acquisition contingencies	2.7	2.7
Total other accrued liabilities	62.9	54.3
Recurring basis | Level 3 | Certificates of deposit
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0	0
Recurring basis | Level 3 | Commercial paper
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0
Recurring basis | Level 3 | Asset-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0	0
Recurring basis | Level 3 | Corporate debt securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0	0
Recurring basis | Level 3 | Municipal bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0	0
Recurring basis | Level 3 | Mortgage-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0
Recurring basis | Level 3 | Foreign government bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments	0	0
Recurring basis | Level 3 | U.S. Treasury
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Short-term investments		0
Recurring basis | Level 3 | Certificates of deposit
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents		0
Recurring basis | Level 3 | Commercial paper
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0	0
Recurring basis | Level 3 | Corporate debt securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0
Recurring basis | Level 3 | Money market funds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0	$ 0
Recurring basis | Level 3 | Municipal bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0
Recurring basis | Level 3 | Foreign government bonds
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0
Recurring basis | Level 3 | U.S. Treasury
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	0
Recurring basis | Level 3 | Asset-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash equivalents	$ 0

Non-Controlling Interest Rede49

Non-Controlling Interest Redeemable Convertible Preferred Stock (Details) $ / shares in Units, $ in Millions	Jul. 31, 2015$ / sharesshares	Mar. 31, 2018USD ($)$ / shares	Apr. 01, 2017USD ($)	Mar. 31, 2018USD ($)d$ / shares	Apr. 01, 2017USD ($)	Jul. 01, 2017USD ($)
Redeemable Noncontrolling Interest [Line Items]
Redemption value		$ 35.8		$ 35.8		$ 35.8
Dividends paid for preferred stock		0.5	$ 0.2	$ 0.7	$ 0.6
Redeemable Convertible Series A Preferred Stock
Redeemable Noncontrolling Interest [Line Items]
Number of years before stock is redeemable at the holders' option				5 years
Redemption value		$ 35.8		$ 35.8
Conversion price per share (usd per share) | $ / shares	$ 24.63
Conversion price equal to the volume weighted average price per share (as a percent)	125.00%
Number of regular-way trading days used to set conversion price | d				5
Liquidation preference per share (usd per share) | $ / shares		$ 1,000		$ 1,000
Annual dividend rate				2.50%
Accrued dividends				$ 0.2		$ 0.2
Redeemable Convertible Series A Preferred Stock | Viavi
Redeemable Noncontrolling Interest [Line Items]
Number of shares sold (in shares) | shares	40,000
Redeemable Convertible Series A Preferred Stock | Amada | Viavi
Redeemable Noncontrolling Interest [Line Items]
Number of shares sold (in shares) | shares	35,805
Number of shares canceled (in shares) | shares	4,195

Convertible Senior Notes - Narr

Convertible Senior Notes - Narrative (Details)	Mar. 08, 2017	Mar. 31, 2017USD ($)$ / shares	Mar. 31, 2018USD ($)d$ / shares	Jul. 01, 2017USD ($)$ / shares
Debt Instrument [Line Items]
Conversion price (usd per share) | $ / shares			$ 24.63	$ 24.63
Convertible Debt | Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
Debt, aggregate principal amount		$ 450,000,000	$ 450,000,000	$ 450,000,000
Debt, stated interest rate		0.25%
Conversion rate	0.0164965
Conversion price (usd per share) | $ / shares		$ 60.62
Conversion price premium percentage		132.50%
Conversion threshold trading days | d			20
Conversion threshold consecutive trading days | d			30
Conversion threshold percentage of stock price trigger			130.00%
Conversion threshold measurement period			5 days
Conversion threshold percentage of conversion rate from measurement period			98.00%
Percentage of principal amount required to be paid upon contingent note repurchase			100.00%
Derivative liability fair value		$ 129,900,000
Residual principal amount of notes before issuance costs		320,100,000
Debt issuance costs		$ 7,700,000
Effective interest rate on the liability component		5.40%	5.40%
Debt, remaining discount amortization period			71 months

Convertible Senior Notes - Sche

Convertible Senior Notes - Schedule of Convertible Notes (Details) - USD ($)	Mar. 31, 2018	Jul. 01, 2017	Mar. 31, 2017
Liability component:
Net carrying amount of the liability component	$ 456,100,000
Convertible Debt | Convertible Senior Notes Due 2024
Liability component:
Principal	450,000,000	$ 450,000,000	$ 450,000,000
Unamortized debt discount	(120,100,000)	(132,500,000)
Net carrying amount of the liability component	$ 329,900,000	$ 317,500,000

Convertible Senior Notes - Inte

Convertible Senior Notes - Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2018	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2017
Debt Instrument [Line Items]
Amortization of the debt discount		$ 12.4	$ 1
Convertible Debt | Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
Contractual interest expense	$ 0.3	0.9
Amortization of the debt discount	4.2	12.4
Total interest expense	$ 4.5	$ 13.3
Effective interest rate on the liability component	5.40%	5.40%		5.40%

Derivative Liability (Details)

Derivative Liability (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017	Jul. 01, 2017
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unrealized loss on derivative liabilities	$ (20.7)	$ (56.6)	$ (8.6)	$ (74.5)
Fair Value Assumptions [Abstract]
Stock price (usd per share)	$ 63.80		$ 63.80		$ 57.05
Conversion price (usd per share)	$ 24.63		$ 24.63		$ 24.63
Expected term (years)			2 years 4 months 13 days		3 years 1 month 10 days
Expected annual volatility			50.00%		48.00%
Risk-free rate			2.31%		1.57%
Preferred yield			8.32%		7.56%
Embedded Derivative Liability | Series A Preferred Stock | Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unrealized loss on derivative liabilities	$ (20.7)	(17.9)	$ (8.6)	(35.8)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of beginning of period	(39.5)	(28.2)	(51.6)	(10.3)	$ (10.3)
Unrealized loss on derivative liability	(20.7)	(17.9)	(8.6)	(35.8)
Balance as of end of period	(60.2)	(46.1)	(60.2)	(46.1)	(51.6)
Embedded Derivative Liability | The 2024 Notes | Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of beginning of period	0	0	0	0	0
Fair value of the embedded derivative for the 2024 Notes at issuance	0	(129.9)	0	(129.9)
Unrealized loss on derivative liability	0	(38.7)	0	(38.7)
Balance as of end of period	$ 0	$ (168.6)	$ 0	$ (168.6)	$ 0

Goodwill and Other Intangible54

Goodwill and Other Intangible Assets - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017	Jul. 01, 2017
Goodwill [Line Items]
Goodwill	$ 11,800,000		$ 11,800,000		$ 11,400,000
Impairment charges			0
Amortization of acquired developed technologies and other intangibles	800,000	$ 1,800,000	2,400,000	$ 5,400,000
Optical Communications
Goodwill [Line Items]
Goodwill	$ 6,300,000		$ 6,300,000		$ 5,900,000

Goodwill and Other Intangible55

Goodwill and Other Intangible Assets - Changes in Goodwill (Details) $ in Millions	9 Months Ended
	Mar. 31, 2018USD ($)
Changes in goodwill
Balance at the beginning of the period	$ 11.4
Foreign currency translation adjustment	0.4
Balance at the end of the period	11.8
Optical Communications
Changes in goodwill
Balance at the beginning of the period	5.9
Foreign currency translation adjustment	0.4
Balance at the end of the period	6.3
Commercial Lasers
Changes in goodwill
Balance at the beginning of the period	5.5
Foreign currency translation adjustment	0
Balance at the end of the period	$ 5.5

Goodwill and Other Intangible56

Goodwill and Other Intangible Assets - Acquired Developed Technology and Other Intangibles (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017	Jul. 01, 2017
Acquired developed technology, customer relationships and other intangibles
Gross Carrying Amount	$ 115.3		$ 115.3		$ 114.9
Accumulated Amortization	(107.2)		(107.2)		(104.8)
Net	8.1		8.1		10.1
Amortization	0.8	$ 1.8	2.4	$ 5.4
Estimated future amortization expense
Remainder of 2018	0.8		0.8
2,019	3.1		3.1
2,020	3		3
2,021	0.5		0.5
2,022	0.5		0.5
Thereafter	0.2		0.2
Total amortization	8.1		8.1
Cost of sales
Acquired developed technology, customer relationships and other intangibles
Amortization	0.8	1.7	2.4	5.1
Operating expenses
Acquired developed technology, customer relationships and other intangibles
Amortization	0	$ 0.1	0	$ 0.3
Acquired developed technology
Acquired developed technology, customer relationships and other intangibles
Gross Carrying Amount	105.9		105.9		105.5
Accumulated Amortization	(97.8)		(97.8)		(95.4)
Net	8.1		8.1		10.1
Other
Acquired developed technology, customer relationships and other intangibles
Gross Carrying Amount	9.4		9.4		9.4
Accumulated Amortization	(9.4)		(9.4)		(9.4)
Net	$ 0		$ 0		$ 0

Restructuring and Related Cha57

Restructuring and Related Charges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Summary of Restructuring Plans
Balance as of beginning of period	$ 0.4	$ 6	$ 3.8	$ 5.7
Charges	0.1	3.1	3.8	10
Payments	(0.5)	(3.8)	(7.6)	(10.4)
Balance as of end of period	$ 0	5.3	$ 0	5.3
Severance costs
Summary of Restructuring Plans
Charges		0.4		2.2
Other Charges
Summary of Restructuring Plans
Charges		$ 2.7		$ 7.8

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017	Jun. 30, 2018
Income Tax Contingency [Line Items]
Provision for (benefit from) income taxes	$ 0	$ 11.6	$ (112.9)	$ 15.4
Released valuation allowance due to recognized tax benefit	207
Decrease in deferred tax assets			83
Estimated tax expense as a result of rate decrease	83
Unrecognized tax benefits liability	$ 10.2		$ 10.2
Forecast
Income Tax Contingency [Line Items]
Blended statutory rate					28.00%

Stock-Based Compensation and 59

Stock-Based Compensation and Stock Plans - Description of Lumentum Stock-Based Benefit Plans and Stock-Based Compensation (Details) - USD ($) $ in Millions	Nov. 04, 2016	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017	Jul. 01, 2017	Aug. 02, 2015	Jun. 23, 2015
Stock-Based Compensation
Common stock authorized for issuance under plan (in shares)								8,500,000
Common stock reserved for future issuance (in shares)							2,100,000
Increase in number of shares that may be issued	3,000,000
Shares of common stock available for grant (in shares)		5,700,000		5,700,000		6,600,000
Impact on the entity's results of operations of recording stock-based compensation by function
Stock-based compensation cost		$ 11	$ 8.1	$ 35.1	$ 25
Stock-based compensation capitalized to inventory				2.1		$ 1.8
Cost of sales
Impact on the entity's results of operations of recording stock-based compensation by function
Stock-based compensation cost		2.4	1.9	9.5	6
Research and development
Impact on the entity's results of operations of recording stock-based compensation by function
Stock-based compensation cost		3.6	3	10.5	8.8
Selling, general and administrative
Impact on the entity's results of operations of recording stock-based compensation by function
Stock-based compensation cost		$ 5	3.2	$ 15.1	10.2
Full Value Awards - Total
Stock-Based Compensation
Stock options and Full Value Awards issued and outstanding (in shares)		2,100,000		2,100,000
Full Value Awards - Total | Minimum
Stock-Based Compensation
Vesting period				1 year
Full Value Awards - Total | Maximum
Stock-Based Compensation
Vesting period				4 years
Options
Stock-Based Compensation
Shares of common stock available for grant (in shares)		5,700,000		5,700,000
Options | Minimum
Stock-Based Compensation
Vesting period				3 years
Stock awards expiration period				5 years
Options | Maximum
Stock-Based Compensation
Vesting period				4 years
Stock awards expiration period				10 years
2015 Purchase Plan
Stock-Based Compensation
Common stock authorized for issuance under plan (in shares)								3,000,000
Shares of common stock available for grant (in shares)		2,400,000		2,400,000
Discount rate provided under purchase plan (as a percent)				15.00%
Look-back period				6 months
Impact on the entity's results of operations of recording stock-based compensation by function
Stock-based compensation cost		$ 0.8	$ 0.7	$ 2.4	$ 2
Restricted Stock Units
Stock-Based Compensation
Granted awards (in shares)				1,000,000
Restricted Stock Units | Minimum
Stock-Based Compensation
Vesting period				1 year
Restricted Stock Units | Maximum
Stock-Based Compensation
Vesting period				4 years
Restricted Stock Awards
Stock-Based Compensation
Granted awards (in shares)				0
Restricted Stock Awards | Minimum
Stock-Based Compensation
Vesting period				1 year
Restricted Stock Awards | Maximum
Stock-Based Compensation
Vesting period				4 years
Performance Stock Units
Stock-Based Compensation
Vesting period				3 years
Granted awards (in shares)				116,788
Impact on the entity's results of operations of recording stock-based compensation by function
Stock-based compensation cost		$ 0.4		$ 1.6

Stock-Based Compensation and 60

Stock-Based Compensation and Stock Plans - Stock Option and Stock Award Activity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Stock-Based Compensation
Stock options exercised (in shares)			41,727
Stock options outstanding (in shares)	3,057		3,057
Awards granted (in shares)	0	0	0	0
Total intrinsic value of awards exercised		$ 1	$ 0.8	$ 4.6
Excess tax benefit associated with stock-based compensation		$ 2.3	0	$ 5.2
Unrecognized stock-based compensation	$ 72.5		$ 72.5
Period for recognition of unamortized expense of stock options			1 year 9 months 18 days
Restricted Stock Units
Number of Shares
Outstanding at the beginning of the period (in shares)			1,900,000
Granted (in shares)			1,000,000
Exercised / Vested (in shares)			(900,000)
Canceled (in shares)			(200,000)
Outstanding at the end of the period (in shares)	1,800,000		1,800,000
Weighted-Average Grant Date Fair Value per Share
Outstanding at the beginning of the period (in dollars per share)			$ 28.04
Granted (in dollars per share)			53.35
Exercised /Vested (in dollars per share)			26.60
Canceled (in dollars per share)			38.23
Outstanding at the end of the period (in dollars per share)	$ 43.08		$ 43.08
Restricted Stock Awards
Number of Shares
Outstanding at the beginning of the period (in shares)			300,000
Granted (in shares)			0
Exercised / Vested (in shares)			(100,000)
Canceled (in shares)			0
Outstanding at the end of the period (in shares)	200,000		200,000
Weighted-Average Grant Date Fair Value per Share
Outstanding at the beginning of the period (in dollars per share)			$ 32.51
Granted (in dollars per share)			0
Exercised /Vested (in dollars per share)			32.51
Canceled (in dollars per share)			0
Outstanding at the end of the period (in dollars per share)	$ 32.51		$ 32.51
Performance Stock Units
Number of Shares
Outstanding at the beginning of the period (in shares)			0
Granted (in shares)			116,788
Exercised / Vested (in shares)			0
Canceled (in shares)			0
Outstanding at the end of the period (in shares)	100,000		100,000
Weighted-Average Grant Date Fair Value per Share
Outstanding at the beginning of the period (in dollars per share)			$ 0
Granted (in dollars per share)			52
Exercised /Vested (in dollars per share)			0
Canceled (in dollars per share)			0
Outstanding at the end of the period (in dollars per share)	$ 52		$ 52

Stock-Based Compensation and 61

Stock-Based Compensation and Stock Plans - Awards Available for Grant (Details) shares in Millions	9 Months Ended
	Mar. 31, 2018shares
Share-Based Compensation Arrangement By Share-based Payment Award, Number Of Shares Available For Grant [Roll Forward]
Beginning balance (in shares)	6.6
Granted (in shares)	(1.1)
Canceled (in shares)	0.2
Ending balance (in shares)	5.7

Stock-Based Compensation and 62

Stock-Based Compensation and Stock Plans - Employee Stock Purchase Plan (ESPP) Activity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Stock-Based Compensation
Compensation expense	$ 11	$ 8.1	$ 35.1	$ 25
Shares issued in ESPP (in shares)	93,044	188,864	93,044	188,864
2015 Purchase Plan
Stock-Based Compensation
Compensation expense	$ 0.8	$ 0.7	$ 2.4	$ 2
Expected term (years)	6 months	6 months	6 months	6 months
Expected volatility	49.90%	46.00%	49.90%	46.00%
Risk-free interest rate	1.42%	0.62%	1.42%	0.62%
Dividend yield	0.00%	0.00%	0.00%	0.00%

Commitments and Contingencies -

Commitments and Contingencies - Operating Leases (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Future minimum operating lease payments
Remainder of 2018	$ 2.9		$ 2.9
2,019	11.9		11.9
2,020	9		9
2,021	5.2		5.2
2,022	3.5		3.5
Thereafter	4.3		4.3
Total minimum operating lease payments	36.8		36.8
Rental expense related to building and equipment	$ 2.8	$ 2.6	$ 9.2	$ 7

Commitments and Contingencies64

Commitments and Contingencies - Capital Lease (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jul. 01, 2017
Property, plant and equipment
Property, plant and equipment, gross	$ 738.6	$ 659.9
Remainder of 2018	4.7
2,019	7.5
2,020	0.4
Total minimum capital lease payments	12.6
Less: amount representing interest	(0.3)
Present value of capital lease obligation	12.3
Capital leased assets
Property, plant and equipment
Property, plant and equipment, gross	$ 15.6

Commitments and Contingencies65

Commitments and Contingencies - Acquisition Contingencies (Details) - Private Company Acquisition $ in Millions	1 Months Ended
	Feb. 28, 2017USD ($)
Acquisitions
Contingent liabilities incurred	$ 3.6
Liabilities incurred	$ 2.7
Transferred contingent liability achievement period	36 months
Amount of purchase price retained as security	$ 0.9

Commitments and Contingencies66

Commitments and Contingencies - Convertible Senior Notes (Details) $ in Millions	Mar. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,019	$ 1.1
2,020	1.1
2,021	1.1
2,022	1.1
Thereafter	451.7
Net carrying amount of the liability component	$ 456.1

Commitments and Contingencies67

Commitments and Contingencies - Purchase Obligations and Product Warranties (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Purchase Obligations
Legally-binding purchase commitment obligations	$ 187.1		$ 187.1
Typical duration of supply agreements with single or limited source vendors			1 year
Product Warranties
Product warranty term			12 months
Changes in warranty reserve
Balance as of beginning of period	9.9	$ 8.7	$ 9.7	$ 2.8
Provision for warranty	2	0.6	4.9	9.3
Utilization of reserve	(4.9)	(1.2)	(7.6)	(4)
Balance as of end of period	7	$ 8.1	$ 7	$ 8.1
Settlement received from vendor	$ 5.1
Minimum
Product Warranties
Product warranty term			6 months
Maximum
Product Warranties
Product warranty term			5 years

Operating Segments and Geogra68

Operating Segments and Geographic Information - Segments Utilized by our CODM (Details) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018USD ($)	Apr. 01, 2017USD ($)	Mar. 31, 2018USD ($)segment	Apr. 01, 2017USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment			2
Information on reportable segments
Net revenue	$ 298.8	$ 255.8	$ 946.6	$ 778.9
Gross profit	97	82.1	336.6	250.8
Gross profit	97	82.1	336.6	250.8
Operating Segments
Information on reportable segments
Net revenue	298.8	255.8	946.6	778.9
Gross profit	108.5	87.9	373	274
Gross profit	108.5	87.9	373	274
Operating Segments | OpComms
Information on reportable segments
Net revenue	246.3	216.1	814.3	671
Gross profit	83.1	71.5	317.1	229.2
Gross profit	83.1	71.5	317.1	229.2
Operating Segments | Lasers
Information on reportable segments
Net revenue	52.5	39.7	132.3	107.9
Gross profit	25.4	16.4	55.9	44.8
Gross profit	25.4	16.4	55.9	44.8
Corporate
Information on reportable segments
Stock-based compensation	(2.4)	(1.9)	(9.5)	(6)
Amortization of intangibles	(0.8)	(1.7)	(2.4)	(5.1)
Other charges related to non-recurring activities	$ (8.3)	$ (2.2)	$ (24.5)	$ (12.1)

Operating Segments and Geogra69

Operating Segments and Geographic Information - Schedule of Products and Services 10% or More of Total Net Revenue (Details) - Product concentration risk - Revenue	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
OpComms
Concentration Risk [Line Items]
Concentration risk percentage	82.40%	84.50%	86.00%	86.10%
OpComms | Telecom
Concentration Risk [Line Items]
Concentration risk percentage	41.00%	64.50%	36.30%	63.00%
OpComms | Datacom
Concentration Risk [Line Items]
Concentration risk percentage	12.10%	15.20%	12.20%	19.40%
OpComms | Consumer and Industrial
Concentration Risk [Line Items]
Concentration risk percentage	29.30%	4.80%	37.50%	3.70%
Lasers
Concentration Risk [Line Items]
Concentration risk percentage	17.60%	15.50%	14.00%	13.90%

Operating Segments and Geogra70

Operating Segments and Geographic Information - Schedule of Revenue by Geographical Region (Details) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2018USD ($)	Apr. 01, 2017USD ($)	Mar. 31, 2018USD ($)region	Apr. 01, 2017USD ($)
Segment Reporting [Abstract]
Number of geographic regions | region			3
Net revenue:
Total net revenue	$ 298.8	$ 255.8	$ 946.6	$ 778.9
Americas
Net revenue:
Total net revenue	$ 70	$ 106.2	$ 189.1	$ 272.1
Americas | Geographic Concentration Risk | Total Net Revenue
Net revenue:
Concentration risk percentage	23.50%	41.60%	20.00%	34.90%
United States
Net revenue:
Total net revenue	$ 26.8	$ 34.7	$ 86.3	$ 106.2
United States | Geographic Concentration Risk | Total Net Revenue
Net revenue:
Concentration risk percentage	9.00%	13.60%	9.10%	13.60%
Mexico
Net revenue:
Total net revenue	$ 41.7	$ 70	$ 97.1	$ 158.5
Mexico | Geographic Concentration Risk | Total Net Revenue
Net revenue:
Concentration risk percentage	14.00%	27.40%	10.30%	20.30%
Other Americas
Net revenue:
Total net revenue	$ 1.5	$ 1.5	$ 5.7	$ 7.4
Other Americas | Geographic Concentration Risk | Total Net Revenue
Net revenue:
Concentration risk percentage	0.50%	0.60%	0.60%	1.00%
Asia Pacific [Member]
Net revenue:
Total net revenue	$ 205.5	$ 119.5	$ 683.3	$ 424.5
Asia Pacific [Member] | Geographic Concentration Risk | Total Net Revenue
Net revenue:
Concentration risk percentage	68.70%	46.70%	72.20%	54.50%
Hong Kong
Net revenue:
Total net revenue	$ 38.7	$ 47.2	$ 133.3	$ 181.2
Hong Kong | Geographic Concentration Risk | Total Net Revenue
Net revenue:
Concentration risk percentage	13.00%	18.50%	14.10%	23.30%
China
Net revenue:
Total net revenue	$ 47.3	$ 8.7	$ 66.8	$ 28.3
China | Geographic Concentration Risk | Total Net Revenue
Net revenue:
Concentration risk percentage	15.80%	3.40%	7.10%	3.60%
Japan
Net revenue:
Total net revenue	$ 34.1	$ 25.9	$ 157.6	$ 78.5
Japan | Geographic Concentration Risk | Total Net Revenue
Net revenue:
Concentration risk percentage	11.40%	10.10%	16.60%	10.10%
South Korea
Net revenue:
Total net revenue	$ 28.8	$ 2.4	$ 126.3	$ 3.5
South Korea | Geographic Concentration Risk | Total Net Revenue
Net revenue:
Concentration risk percentage	9.60%	0.90%	13.30%	0.40%
Other Asia-Pacific
Net revenue:
Total net revenue	$ 56.6	$ 35.3	$ 199.3	$ 133
Other Asia-Pacific | Geographic Concentration Risk | Total Net Revenue
Net revenue:
Concentration risk percentage	18.90%	13.80%	21.10%	17.10%
EMEA
Net revenue:
Total net revenue	$ 23.3	$ 30.1	$ 74.2	$ 82.3
EMEA | Geographic Concentration Risk | Total Net Revenue
Net revenue:
Concentration risk percentage	7.80%	11.80%	7.80%	10.60%

Operating Segments and Geogra71

Operating Segments and Geographic Information - Concentration Risk for Major Customers (Details) - Customer concentration risk - Revenue	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Customer A
Concentration Risk [Line Items]
Concentration risk percentage	25.00%		33.00%
Customer B
Concentration Risk [Line Items]
Concentration risk percentage	12.00%	12.00%	11.00%	18.00%
Customer C
Concentration Risk [Line Items]
Concentration risk percentage	13.00%	27.00%		20.00%
Customer D
Concentration Risk [Line Items]
Concentration risk percentage				12.00%

Operating Segments and Geogra72

Operating Segments and Geographic Information - Schedule of Long-lived Assets by Geographical Region (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jul. 01, 2017
Property, plant and equipment, net
Property, plant and equipment, net	$ 301.8	$ 273.5
United States
Property, plant and equipment, net
Property, plant and equipment, net	97.4	88.2
China
Property, plant and equipment, net
Property, plant and equipment, net	76.9	82.5
Thailand
Property, plant and equipment, net
Property, plant and equipment, net	92.9	85.3
Other countries
Property, plant and equipment, net
Property, plant and equipment, net	$ 34.6	$ 17.5

Operating Segments and Geogra73

Operating Segments and Geographic Information - Concentration Risk for Inventory Purchases (Details) - Supplier concentration risk - Cost of goods, inventory	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Vendor A
Concentration Risk [Line Items]
Concentration risk percentage	48.00%	50.00%	42.00%	52.00%
Vendor B
Concentration Risk [Line Items]
Concentration risk percentage	19.00%	26.00%	19.00%	26.00%
Vendor C
Concentration Risk [Line Items]
Concentration risk percentage	18.00%		23.00%
Vendor D
Concentration Risk [Line Items]
Concentration risk percentage		16.00%		14.00%