Coherent 10-Q 11 May 16 2016 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Apr. 02, 2016	May. 09, 2016
DEI [Abstract]
Entity Registrant Name	COHERENT INC
Trading Symbol	COHR
Entity Central Index Key	21,510
Document Type	10-Q
Document Period End Date	Apr. 2, 2016
Amendment Flag	false
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--10-01
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		24,291,591

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 02, 2016	Apr. 04, 2015	Apr. 02, 2016	Apr. 04, 2015
Income Statement [Abstract]
Net sales	$ 199,882	$ 203,721	$ 390,157	$ 404,336
Cost of sales	111,283	120,417	217,660	238,713
Gross profit	88,599	83,304	172,497	165,623
Operating expenses:
Research and development	20,955	21,024	40,095	40,197
Selling, general and administrative	40,940	39,482	77,714	77,623
Amortization of intangible assets	700	666	1,401	1,362
Total operating expenses	62,595	61,172	119,210	119,182
Income from operations	26,004	22,132	53,287	46,441
Other income (expense):
Interest and dividend income	263	161	503	257
Interest expense	(30)	(14)	(45)	(25)
Other - net	(2,013)	1,843	(2,460)	1,073
Total other income (expense), net	(1,780)	1,990	(2,002)	1,305
Income before income taxes	24,224	24,122	51,285	47,746
Provision for income taxes	6,443	5,709	13,218	11,903
Net income	$ 17,781	$ 18,413	$ 38,067	$ 35,843
Net income per share:
Basic	$ 0.74	$ 0.75	$ 1.58	$ 1.44
Diluted	$ 0.73	$ 0.74	$ 1.57	$ 1.43
Shares used in computation:
Basic	24,137	24,709	24,066	24,823
Diluted	24,362	24,891	24,299	25,042

Condensed Consolidated Stateme3

Condensed Consolidated Statements of Comprehensive Income (Loss) (unaudited) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Apr. 02, 2016	Apr. 04, 2015	Apr. 02, 2016	Apr. 04, 2015
Statement of Comprehensive Income [Abstract]
Net income		$ 17,781	$ 18,413	$ 38,067	$ 35,843
Other comprehensive income (loss):
Translation adjustment, net of taxes	[1],[2]	13,568	(33,280)	5,062	(47,799)
Net gain (loss) on derivative instruments, net of taxes	[1],[3]	2	175	(28)	550
Changes in unrealized gains (losses) on available-for-sale securities, net of taxes	[1],[4]	2,325	274	2,463	201
Other comprehensive income (loss), net of tax	[1]	15,895	(32,831)	7,497	(47,048)
Comprehensive income (loss)		$ 33,676	$ (14,418)	$ 45,564	$ (11,205)
[1]	Reclassification adjustments were not significant during the three and six months ended April 2, 2016 and April 4, 2015.
[2]	Tax expenses of $465 and $119 were provided on translation adjustments during the three and six months ended April 2, 2016, respectively. Tax benefits of $1,110 and $1,862 were provided on translation adjustments during the three and six months ended April 4, 2015, respectively.
[3]	Tax expenses (benefits) of $1 and $(17) were provided on net gains (losses) on derivative instruments during the three and six months ended April 2, 2016, respectively. Tax expenses of $102 and $319 were provided on net gains (losses) on derivative instruments during the three and six months ended April 4, 2015, respectively.
[4]	Tax expenses of $1,357 and $1,437 were provided on changes in unrealized gains on available-for-sale securities during the three and six months ended April 2, 2016, respectively. Tax expenses of $158 and $119 were provided on changes in unrealized gains on available-for-sale securities during the three and six months ended April 4, 2015, respectively.

Condensed Consolidated Stateme4

Condensed Consolidated Statements of Comprehensive Income (Loss) (unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 02, 2016	Apr. 04, 2015	Apr. 02, 2016	Apr. 04, 2015
Statement of Comprehensive Income [Abstract]
Translation Adjustment Functional to Reporting Currency, Tax Expense (Benefit)	$ 465	$ (1,110)	$ 119	$ (1,862)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	1	102	(17)	319
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	$ 1,357	$ 158	$ 1,437	$ 119

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Apr. 02, 2016	Oct. 03, 2015
Current assets:
Cash and cash equivalents	$ 157,176	$ 130,607
Short-term investments	203,882	194,908
Accounts receivable—net of allowances of $2,955 and $3,015, respectively	150,409	142,260
Inventories	179,067	156,614
Prepaid expenses and other assets	34,602	28,294
Total current assets	725,136	652,683
Property and equipment, net	108,575	102,445
Goodwill	102,876	101,817
Intangible assets, net	18,510	22,776
Other assets	93,446	89,226
Total assets	1,048,543	968,947
Current liabilities:
Short-term borrowings	5,000	0
Accounts payable	43,458	33,379
Income taxes payable	11,545	4,279
Other current liabilities	89,808	84,932
Total current liabilities	149,811	122,590
Other long-term liabilities	$ 49,183	$ 49,939
Commitments and contingencies (Note 11)
Common stock, par value $.01 per share:
Authorized—500,000 shares, Outstanding—24,218 shares and 24,950 shares, respectively	$ 241	$ 238
Additional paid-in capital	136,171	128,607
Accumulated other comprehensive income (loss)	(2,016)	(9,513)
Retained earnings	715,153	677,086
Total stockholders’ equity	849,549	796,418
Total liabilities and stockholders’ equity	$ 1,048,543	$ 968,947

Condensed Consolidated Balance6

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Apr. 02, 2016	Oct. 03, 2015
Condensed Consolidated Balance Sheets (Parenthetical) [Abstract]
Allowance for Doubtful Accounts Receivable	$ 2,955	$ 3,015
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	500,000,000	500,000,000
Common Stock, Shares, Outstanding	24,218,000	23,970,000

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Apr. 02, 2016	Apr. 04, 2015
Cash flows from operating activities:
Net income	$ 38,067	$ 35,843
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	12,883	12,436
Amortization of intangible assets	4,169	4,216
Deferred income taxes	(5,653)	6,483
Stock-based compensation	9,132	9,172
Other non-cash (income) expense	(12)	384
Changes in assets and liabilities, net of effect of acquisitions:
Accounts receivable	(5,333)	6,441
Inventories	(21,063)	6,114
Prepaid expenses and other assets	(4,857)	(13,921)
Other assets	1,984	582
Accounts payable	7,516	557
Income taxes payable/receivable	5,979	(9,871)
Other current liabilities	3,821	21,894
Other long-term liabilities	(1,079)	84
Net cash provided by operating activities	45,554	80,414
Cash flows from investing activities:
Purchases of property and equipment	(16,256)	(12,210)
Proceeds from dispositions of property and equipment	180	974
Purchases of available-for-sale securities	(84,629)	(177,704)
Proceeds from sales and maturities of available-for-sale securities	79,470	175,436
Net cash used in investing activities	(21,235)	(13,504)
Cash flows from financing activities:
Short-term borrowings	34,792	19,485
Repayments of short-term borrowing	(29,792)	(19,485)
Debt issuance costs	(2,137)	0
Issuance of common stock under employee stock option and purchase plans	3,686	3,701
Repurchase of common stock	0	(25,009)
Net settlement of restricted common stock	(5,344)	(5,235)
Net cash provided by (used in) financing activities	1,205	(26,543)
Effect of exchange rate changes on cash and cash equivalents	1,045	(16,503)
Net increase in cash and cash equivalents	26,569	23,864
Cash and cash equivalents, beginning of period	130,607	91,217
Cash and cash equivalents, end of period	157,176	115,081
Unpaid property and equipment purchases	$ 3,800	$ 828

Basis of Presentation

Basis of Presentation	6 Months Ended
	Apr. 02, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	BASIS OF PRESENTATION The accompanying unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations. These interim condensed consolidated financial statements and notes thereto should be read in conjunction with the Coherent, Inc. (referred to herein as the “Company,” “we,” “our,” “us” or “Coherent”) condensed consolidated financial statements and notes thereto filed on Form 10-K for the fiscal year ended October 3, 2015 . In the opinion of management, all adjustments necessary for a fair presentation of financial condition and results of operation as of and for the periods presented have been made and include only normal recurring adjustments. Interim results of operations are not necessarily indicative of results to be expected for the year or any other interim periods. Our fiscal year ends on the Saturday closest to September 30 and our second fiscal quarters include 13 and 14 weeks of operations in fiscal 2016 and 2015, respectively. Fiscal year 2016 includes 52 weeks and fiscal year 2015 includes 53 weeks.

Recent Accounting Standards

Recent Accounting Standards	6 Months Ended
	Apr. 02, 2016
Accounting Policies [Abstract]
Recent Accounting Standards	RECENT ACCOUNTING STANDARDS Adoption of New Accounting Pronouncements In November 2015, the FASB issued amended guidance that clarifies that in a classified statement of financial position, an entity shall classify deferred tax liabilities and assets as noncurrent amounts. The new guidance supersedes ASC 740-10-45-5 which required the valuation allowance for a particular tax jurisdiction be allocated between current and noncurrent deferred tax assets for that tax jurisdiction on a pro rata basis. The new standard will become effective for our fiscal year beginning October 2, 2017. We elected to early adopt the standard retrospectively in the first quarter of fiscal 2016, which resulted in the reclassification of $28.1 million from current deferred income tax assets to non-current deferred income tax assets and non-current deferred income tax liabilities as of October 3, 2015. In April 2015, the FASB issued amended guidance that simplifies the presentation of debt issuance costs by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amended guidance. The new standard will become effective for our fiscal year beginning October 2, 2016. We elected to early adopt the standard in the second quarter of fiscal 2016 to record the debt issuance costs of $2.1 million in other assets for the debt commitment we entered into in the second quarter of fiscal 2016. Recently Issued Accounting Pronouncements In March 2016, the FASB issued amended guidance that simplifies several aspects of the accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. Under the new guidance, an entity recognizes all excess tax benefits and tax deficiencies as income tax expense or benefit in the income statement. This change eliminates the notion of the APIC pool and significantly reduces the complexity and cost of accounting for excess tax benefits and tax deficiencies. In addition, excess tax benefits and tax deficiencies are considered discrete items in the reporting period they occur and are not included in the estimate of an entity’s annual effective tax rate. The new standard will become effective for our fiscal year beginning October 2, 2017. We are currently assessing the impact of this amended guidance and the timing of adoption. In February 2016, the FASB issued amended guidance to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The new guidance clarifies the criteria for distinguishing between a finance lease and operating lease, as well as classification between the two types of leases, which is substantially unchanged from the previous lease guidance. Further, the new guidance requires a lessee to recognize in the statement of financial position a liability to make lease payments (the lease liability) and a right-of-use asset, initially measured at the present value of the lease payments. For finance leases, a lessee should recognize interest on the lease liability separately from amortization of the right-of-use asset. For operating leases, a lessee should recognize a single lease cost, calculated so that the cost of the lease is allocated over the lease term on a generally straight-line basis. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election not to recognize lease assets and lease liabilities. The new standard will become effective for our fiscal year beginning September 29, 2019. We are currently assessing the impact of this amended guidance and the timing of adoption. In January 2016, the FASB issued amended guidance that revises the recognition and measurement of financial instruments. The new guidance requires equity investments (except those accounted for under the equity method of accounting, or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income, requires public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes, requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset, and eliminates the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost. The new standard will become effective for our fiscal year beginning September 30, 2018. We are currently assessing the impact of this amended guidance and the timing of adoption.

Business Combinations

Business Combinations	6 Months Ended
	Apr. 02, 2016
Business Combinations [Abstract]
Business Combinations	BUSINESS COMBINATIONS Rofin-Sinar Technologies, Inc. On March 16, 2016, we entered into a definitive agreement to acquire Rofin-Sinar Technologies, Inc. ("Rofin"), one of the world's leading developers and manufacturers of high-performance industrial laser sources and laser-based solutions and components. The acquisition will be an all-cash transaction at a price of $32.50 per share of Rofin common stock for a total approximate offer value of $942 million before fees and transaction costs. The completion of the acquisition is subject to customary closing conditions, including regulatory approvals. Fiscal 2015 Acquisitions Raydiance, Inc. On July 24, 2015, we acquired certain assets of Raydiance, Inc. ("Raydiance") for approximately $5.0 million , excluding transaction costs. Raydiance manufactured complete tools and lasers for ultrafast processing systems and subsystems in the precision micromachining processing market. The Raydiance assets have been included in our Specialty Lasers and Systems segment. Our allocation of the purchase price is as follows (in thousands): Tangible assets $ 1,048 Goodwill 1,552 Intangible assets: Existing technology 800 Customer lists 1,600 Total $ 5,000 The purchase price allocated to goodwill was finalized in the first quarter of fiscal 2016, with an increase of $0.4 million and a corresponding decrease of $0.4 million to tangible assets, and has been updated from the preliminary allocation in the fourth quarter of fiscal 2015. Results of operations for the business have been included in our consolidated financial statements subsequent to the date of acquisition and pro forma results of operations in accordance with authoritative guidance for prior periods have not been presented because the effect of the acquisition was not material to our prior period consolidated financial results. The identifiable intangible assets are being amortized over their respective useful lives o f three to five years. None of the goodwill from this purchase is deductible for tax purposes. We expensed $0.1 million of acquisition-related costs as selling, general and administrative expenses in our consolidated statements of operations for our fiscal year 2015. Tinsley Optics On July 27, 2015, we acquired the assets and certain liabilities of the Tinsley Optics ("Tinsley") business from L-3 Communications Corporation for approximately $4.3 million , excluding transaction costs. Tinsley is a specialized manufacturer of high precision optical components and subsystems sold primarily in the aerospace and defense industry. Tinsley manufactures the large form factor optics for our excimer laser annealing systems. Tinsley has been included in our Specialty Lasers and Systems segment. Our allocation of the purchase price is as follows (in thousands): Tangible assets: Inventories $ 2,240 Accounts receivable 2,263 Prepaid expenses and other assets 1,132 Property and equipment 2,451 Liabilities assumed (1,702 ) Deferred tax liabilities (768 ) Gain on business combination (1,316 ) Total $ 4,300 The purchase price was lower than the fair value of net assets purchased, resulting in a gain of $1.3 million recorded as a separate line item in our consolidated statements of operations for our fiscal year 2015. We reassessed the recognition and measurement of identifiable assets acquired and liabilities assumed and concluded that all acquired assets and assumed liabilities were recognized and that the valuation procedures and resulting measures were appropriate. Results of operations for the business have been included in our consolidated financial statements subsequent to the date of acquisition and pro forma results of operations in accordance with authoritative guidance for prior periods have not been presented because the effect of the acquisition was not material to our prior period consolidated financial results. The gain from the bargain purchase is not subject to income taxation. We expensed $0.4 million of acquisition-related costs as selling, general and administrative expenses in our consolidated statements of operations for our fiscal year 2015.

Fair Values

Fair Values	6 Months Ended
	Apr. 02, 2016
Fair Value Disclosures [Abstract]
Fair Values	4. FAIR VALUES We have not changed our valuation techniques in measuring the fair value of any financial assets and liabilities during the period. We recognize transfers between levels within the fair value hierarchy, if any, at the end of each quarter. There were no transfers between levels during the periods presented. As of April 2, 2016 and October 3, 2015 , we did not have any assets or liabilities valued based on Level 3 valuations. Financial assets and liabilities measured at fair value as of April 2, 2016 and October 3, 2015 are summarized below (in thousands): Aggregate Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Aggregate Fair Value Quoted Prices Significant Other Observable Inputs April 2, 2016 October 3, 2015 (Level 1) (Level 2) (Level 1) (Level 2) Assets: Cash equivalents: Money market fund deposits $ 32,184 $ 32,184 $ — $ 8,297 $ 8,297 $ — Short-term investments: U.S. Treasury and agency obligations (2) $ 140,766 $ — $ 140,766 $ 150,748 $ — $ 150,748 Corporate notes and obligations (2) 35,190 — 35,190 17,942 — 17,942 Commercial paper (2) 7,464 — 7,464 9,740 — 9,740 Equity securities (1) 20,462 20,462 — 16,478 16,478 — Prepaid and other assets: Foreign currency contracts (3) 3,152 — 3,152 258 — 258 Mutual funds — Deferred comp and supplemental plan (4) 12,301 12,301 — 13,891 13,891 — Total $ 251,519 $ 64,947 $ 186,572 $ 217,354 $ 38,666 $ 178,688 Liabilities: Other current liabilities: Foreign currency contracts (3) $ (1,904 ) $ — $ (1,904 ) $ (239 ) $ — $ (239 ) Total $ 249,615 $ 64,947 $ 184,668 $ 217,115 $ 38,666 $ 178,449 ___________________________________________________ (1) Valuations are based upon quoted market prices. (2) Valuations are based upon quoted market prices in active markets involving similar assets. The market inputs used to value these instruments generally consist of market yields, reported trades, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. Pricing sources include industry standard data providers, security master files from large financial institutions, and other third party sources which are input into a distribution-curve-based algorithm to determine a daily market value. This creates a “consensus price” or a weighted average price for each security. (3) The principal market in which we execute our foreign currency contracts is the institutional market in an over-the-counter environment with a relatively high level of price transparency. The market participants usually are large commercial banks. Our foreign currency contracts’ valuation inputs are based on quoted prices and quoted pricing intervals from public data sources and do not involve management judgment. At April 2, 2016 , prepaid expenses and other assets include $3,152 non-designated forward contracts; other current liabilities include $1,904 non-designated forward contracts. At October 3, 2015 , prepaid expenses and other assets include $217 non-designated forward contracts and $41 foreign currency contracts designated for cash flow hedges, respectively; other current liabilities include $239 non-designated forward contracts and $0 foreign currency contracts designated for cash flow hedges respectively. See Note 6, "Derivative Instruments and Hedging Activities". (4) The fair value of mutual funds is determined based on quoted market prices. Securities traded on a national exchange are stated at the last reported sales price on the day of valuation; other securities traded in over-the-counter markets and listed securities for which no sale was reported on that date are stated as the last quoted bid price.

Short-Term Investments

Short-Term Investments	6 Months Ended
	Apr. 02, 2016
Cash, Cash Equivalents, and Short-term Investments [Abstract]
Short-Term Investments	SHORT-TERM INVESTMENTS We consider all highly liquid investments with maturities of three months or less at the time of purchase to be cash equivalents. Investments classified as available-for-sale are reported at fair value with unrealized gains and losses, net of related income taxes, recorded as a separate component of other comprehensive income (“OCI”) in stockholders’ equity until realized. Interest and amortization of premiums and discounts for debt securities are included in interest income. Gains and losses on securities sold are determined based on the specific identification method and are included in other income (expense). Cash, cash equivalents and short-term investments consist of the following (in thousands): April 2, 2016 Cost Basis Unrealized Gains Unrealized Losses Fair Value Cash and cash equivalents $ 157,176 $ — $ — $ 157,176 Short-term investments: Available-for-sale securities: Commercial paper $ 7,464 $ — $ — $ 7,464 U.S. Treasury and agency obligations 139,943 854 (31 ) 140,766 Corporate notes and obligations 35,093 104 (7 ) 35,190 Equity Securities 15,269 5,193 — 20,462 Total short-term investments $ 197,769 $ 6,151 $ (38 ) $ 203,882 October 3, 2015 Cost Basis Unrealized Gains Unrealized Losses Fair Value Cash and cash equivalents $ 130,607 $ — $ — $ 130,607 Short-term investments: Available-for-sale securities: Commercial paper $ 9,740 $ — $ — $ 9,740 U.S. Treasury and agency obligations 149,708 1,040 — 150,748 Corporate notes and obligations 17,892 52 (2 ) 17,942 Equity securities 15,269 1,209 — 16,478 Total short-term investments $ 192,609 $ 2,301 $ (2 ) $ 194,908 None of the unrealized losses as of April 2, 2016 or October 3, 2015 were considered to be other-than-temporary impairments. The amortized cost and estimated fair value of available-for-sale investments in debt securities as of April 2, 2016 and October 3, 2015 classified as short-term investments on our condensed consolidated balance sheet were as follows (in thousands): April 2, 2016 October 3, 2015 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Investments in available-for-sale debt securities due in less than one year $ 163,210 $ 164,061 $ 148,088 $ 149,100 Investments in available-for-sale debt securities due in one to five years (1) $ 19,290 $ 19,359 $ 29,252 $ 29,330 (1) Classified as short-term investments because these securities are highly liquid and can be sold at any time. During the three and six months ended April 2, 2016 , we received proceeds totaling $13.5 million and $28.6 million , respectively, from the sale of available-for-sale securities and realized gross gains of less than $0.1 million and $0.1 million , respectively. During the three and six months ended April 4, 2015 , we received proceeds totaling $48.3 million and $77.8 million , respectively, from the sale of available-for-sale securities and realized gross gains of less than $0.1 million and $0.1 million , respectively.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	6 Months Ended
	Apr. 02, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES We maintain operations in various countries outside of the United States and have foreign subsidiaries that manufacture and sell our products in various global markets. The majority of our sales are transacted in U.S. dollars. However, we do generate revenues in other currencies, primarily the Euro, Japanese Yen, South Korean Won and Chinese Renminbi (RMB). As a result, our earnings, cash flows and cash balances are exposed to fluctuations in foreign currency exchange rates. We attempt to limit these exposures through financial market instruments. We utilize derivative instruments, primarily forward contracts with maturities of two months or less, to manage our exposure associated with anticipated cash flows and net asset and liability positions denominated in foreign currencies. Gains and losses on the forward contracts are mitigated by gains and losses on the underlying instruments. We do not use derivative financial instruments for speculative or trading purposes. The credit risk amounts represent the Company’s gross exposure to potential accounting loss on derivative instruments that are outstanding or unsettled if all counterparties failed to perform according to the terms of the contract, based on then-current currency or interest rates at each respective date. For derivative instruments that are not designated as hedging instruments, gains and losses are recognized in other income (expense). Non-Designated Derivatives The outstanding notional contract and fair value asset (liability) amounts of non-designated hedge contracts, with maximum maturity of two months, are as follows (in thousands): U.S. Notional Contract Value U.S. Fair Value April 2, 2016 October 3, 2015 April 2, 2016 October 3, 2015 Euro currency hedge contracts Purchase $ 63,507 $ 52,699 $ 2,919 $ 33 Japanese Yen currency hedge contracts Purchase $ 2,000 $ 558 $ 66 $ 8 Sell $ (36,480 ) $ (15,804 ) $ (406 ) $ (84 ) South Korean Won currency hedge contracts Purchase $ — $ 253 $ — $ — Sell $ (15,872 ) $ (17,747 ) $ (1,154 ) $ 30 Chinese RMB currency hedge contracts Sell $ (10,538 ) $ (10,900 ) $ (193 ) $ (106 ) Other foreign currency hedge contracts Purchase $ 4,313 $ 3,283 $ 167 $ (49 ) Sell $ (2,070 ) $ (5,835 ) $ (151 ) $ 146 Designated Derivatives Cash flow hedges related to anticipated transactions are designated and documented at the inception of the hedge when we enter into contracts for specific future transactions. Cash flow hedges are evaluated for effectiveness quarterly. The effective portion of the gain or loss on these hedges is reported as a component of OCI in stockholder's equity and is reclassified into earnings when the underlying transaction affects earnings. We had no cash flow hedges outstanding at April 2, 2016 . Changes in the fair value of currency forward contracts due to changes in time value are excluded from the assessment of effectiveness and recognized in other income (expense) as incurred. We classify the cash flows from the foreign exchange forward contracts that are accounted for as cash flow hedges in the same section as the underlying item, primarily within cash flows from operating activities since we do not designate our cash flow hedges as investing or financing activities. The outstanding notional contract and fair value asset (liability) amounts of designated cash flow hedge contracts, with maximum maturity of thirteen months, are as follows (in thousands): U.S. Notional Contract Value U.S. Fair Value April 2, 2016 October 3, 2015 April 2, 2016 October 3, 2015 Japanese Yen currency hedge contracts Sell $ — $ (2,093 ) $ — $ 41 We have entered into certain derivative forward contracts to sell Japanese Yen and buy Euro to hedge revenue exposures related to our photonics-based solutions in Asia. In order to facilitate the hedge, we transact with counterparties in the U.S. directly and then allocate the hedge contracts to our affiliates through a back-to-back relationship with our German subsidiary. The German subsidiary designates these hedge contracts as cash flow hedges under ASC 815, none of which were outstanding at April 2, 2016 . The fair value of our derivative instruments is included in prepaid expenses and other assets and in other current liabilities in our Condensed Consolidated Balance Sheets (see Note 4 "Fair Values"). The locations and amounts of designated and non-designated derivative instruments' gains and losses in the condensed consolidated financial statements for the indicated periods were as follows (in thousands): Location in financial statements Three Months Ended Six Months Ended April 2, 2016 April 4, 2015 April 2, 2016 April 4, 2015 Derivatives designated as hedging instruments Gains(losses) in OCI on derivatives (effective portion), after tax OCI $ 2 $ 175 $ (28 ) $ 550 Losses reclassified from OCI into income (effective portion) Cost of sales $ — $ (1,106 ) $ — $ (1,720 ) Gains(losses) reclassified from OCI into income (effective portion) Revenue $ (58 ) $ (92 ) $ (58 ) $ 208 Losses recognized in income on derivatives (ineffective portion and amount excluded from effectiveness testing) Other income(expense) $ (1 ) $ (77 ) $ (30 ) $ (112 ) Derivatives not designated as hedging instruments Losses recognized in income Other income(expense) $ (180 ) $ (5,413 ) $ (2,511 ) $ (6,125 ) During the first quarter of fiscal 2016 we recognized a loss of $31 in other income (expense) as ineffectiveness related to a portion of an anticipated hedged transaction that failed to occur within the original hedge period plus two months. During the three and six months ended April 4, 2015 we recognized a loss of $106 in other income (expense) as ineffectiveness related to a portion of an anticipated hedged transaction that failed to occur within the original hedge period plus two months. The remainder of the hedged transactions occurred as expected and effective amounts were recognized in revenue as disclosed in the above table. The amounts that are reclassified from OCI to earnings are generally offset by the recognition of the hedged transactions (e.g., anticipated cost of sales) in earnings, thereby achieving the realization of prices contemplated by the underlying risk management strategies and vary from the expected amounts presented above as a result of changes in foreign exchange rates. To mitigate credit risk in derivative transactions, we enter into master netting arrangements that allow each counterparty in the arrangements to net settle amounts of multiple and separate derivative transactions under certain conditions. We present the fair value of derivative assets and liabilities within our condensed consolidated balance sheet on a gross basis even when derivative transactions are subject to master netting arrangements and may otherwise qualify for net presentation. Our derivative contracts do not contain any credit risk related contingent features and do not require collateral or other security to be furnished by us or the counterparties. Offsetting of Financial Assets/Liabilities under Master Netting Agreements with Derivative Counterparties as of April 2, 2016 and October 3, 2015 (in thousands): Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets Gross Amounts of Recognized Derivative Assets Gross Amounts Offset in the Condensed Consolidated Balance Sheets Net Amounts of Derivative Assets Presented in the Condensed Consolidated Balance Sheets Financial Instruments (1) Cash Collateral Received Net Amounts As of April 2, 2016: Foreign exchange contracts $ 3,152 $ — $ 3,152 $ (1,186 ) $ — $ 1,966 As of October 3, 2015: Foreign exchange contracts $ 258 $ — $ 258 $ (116 ) $ — $ 142 (1) The balances at April 2, 2016 and October 3, 2015 were related to derivative liabilities which are allowed to be net settled against derivative assets in accordance with the master netting agreements. Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets Gross Amounts of Recognized Derivative Liabilities Gross Amounts Offset in the Condensed Consolidated Balance Sheets Net Amounts of Derivative Liabilities Presented in the Condensed Consolidated Balance Sheets Financial Instruments (1) Cash Collateral Paid Net Amounts As of April 2, 2016: Foreign exchange contracts $ (1,904 ) $ — $ (1,904 ) $ 1,186 $ — $ (718 ) As of October 3, 2015: Foreign exchange contracts $ (239 ) $ — $ (239 ) $ 116 $ — $ (123 ) (1) The balances at April 2, 2016 and October 3, 2015 were related to derivative assets which are allowed to be net settled against derivative liabilities in accordance with the master netting agreements.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Apr. 02, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	GOODWILL AND INTANGIBLE ASSETS During the six months ended April 2, 2016 , we noted no indications of impairment or triggering events to cause us to review goodwill for potential impairment. We will conduct our annual goodwill testing during the fourth fiscal quarter. The changes in the carrying amount of goodwill by segment for the period from October 3, 2015 to April 2, 2016 are as follows (in thousands): Specialty Lasers and Systems Commercial Lasers and Components Total Balance as of October 3, 2015 $ 95,454 $ 6,363 $ 101,817 Translation adjustments and other 1,059 — 1,059 Balance as of April 2,2016 $ 96,513 $ 6,363 $ 102,876 Components of our amortizable intangible assets are as follows (in thousands): April 2, 2016 October 3, 2015 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Existing technology $ 71,384 $ (58,701 ) $ 12,683 $ 71,365 $ (55,452 ) $ 15,913 Customer lists 16,141 (10,733 ) 5,408 16,099 (9,661 ) 6,438 Trade name 393 (353 ) 40 399 (349 ) 50 In-process research & development 379 — 379 375 — 375 Total $ 88,297 $ (69,787 ) $ 18,510 $ 88,238 $ (65,462 ) $ 22,776 For accounting purposes, when an intangible asset is fully amortized, it is removed from the disclosure schedule. Amortization expense for intangible assets for the six months ended April 2, 2016 and April 4, 2015 was $4.2 million and $4.2 million , respectively, which includes $3.1 million and $3.3 million , respectively, for amortization of existing technology. The change in the accumulated amortization also includes $0.1 million and $3.5 million of foreign exchange impact for the six months ended April 2, 2016 and April 4, 2015 , respectively. At April 2, 2016 , estimated amortization expense for the remainder of fiscal 2016 , the next five succeeding fiscal years and all fiscal years thereafter are as follows (in thousands): Estimated Amortization Expense 2016 (remainder) $ 3,925 2017 7,136 2018 4,362 2019 2,228 2020 696 2021 54 Thereafter 109 Total $ 18,510

Balance Sheet Details

Balance Sheet Details	6 Months Ended
	Apr. 02, 2016
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Details	BALANCE SHEET DETAILS Inventories consist of the following (in thousands): April 2, October 3, Purchased parts and assemblies $ 54,339 $ 50,182 Work-in-process 70,632 56,225 Finished goods 54,096 50,207 Total inventories $ 179,067 $ 156,614 Prepaid expenses and other assets consist of the following (in thousands): April 2, October 3, Prepaid and refundable income taxes $ 9,880 $ 8,846 Other taxes receivable 7,177 6,574 Prepaid expenses and other assets 17,545 12,874 Total prepaid expenses and other assets $ 34,602 $ 28,294 Other assets consist of the following (in thousands): April 2, October 3, Assets related to deferred compensation arrangements $ 23,352 $ 25,131 Deferred tax assets 64,027 60,254 Other assets 6,067 3,841 Total other assets $ 93,446 $ 89,226 For our $850.0 million debt financing commitment with Barclays (See Note 9 "Short-term Borrowings"), we paid $2.1 million of debt issuance costs in the second quarter of fiscal 2016 and recorded it to other assets. Other current liabilities consist of the following (in thousands): April 2, October 3, Accrued payroll and benefits $ 37,706 $ 35,504 Deferred revenue 17,772 16,474 Warranty reserve 14,972 15,308 Accrued expenses and other 11,908 10,965 Other taxes payable 5,586 4,888 Customer deposits 1,864 1,793 Total other current liabilities $ 89,808 $ 84,932 Components of the reserve for warranty costs during the first six months of fiscal 2016 and 2015 were as follows (in thousands): Six Months Ended April 2, April 4, Beginning balance $ 15,308 $ 16,961 Additions related to current period sales 10,412 11,618 Warranty costs incurred in the current period (10,693 ) (10,822 ) Adjustments to accruals related to foreign exchange and other (55 ) (1,816 ) Ending balance $ 14,972 $ 15,941 Other long-term liabilities consist of the following (in thousands): April 2, October 3, Long-term taxes payable $ 7,823 $ 7,651 Deferred compensation 24,938 26,691 Deferred tax liabilities 2,259 2,717 Deferred income 3,722 3,149 Asset retirement obligations liability 2,726 2,654 Other long-term liabilities 7,715 7,077 Total other long-term liabilities $ 49,183 $ 49,939

Short-Term Borrowings

Short-Term Borrowings	6 Months Ended
	Apr. 02, 2016
Short-term Debt [Abstract]
Short-Term Borrowings	SHORT-TERM BORROWINGS We have several lines of credit which allow us to borrow in the applicable local currency. We have a total of $13.7 million of unsecured foreign lines of credit as of April 2, 2016 . At April 2, 2016 , we had used $2.0 million of these available foreign lines of credit as guarantees. These credit facilities were used in Europe and Japan during the second fiscal quarter of 2016 . In addition, our domestic line of credit consists of a $50.0 million unsecured revolving credit account. The agreement will expire on May 31, 2017. The line of credit is subject to covenants related to financial ratios and tangible net worth with which we are currently in compliance. We have an outstanding balance of $5.0 million and have used $1.1 million for letters of credit against our domestic line of credit as of April 2, 2016 . On March 16, 2016, we entered into a debt commitment letter with Barclays Bank PLC ("Barclays") and on April 5, 2016, entered into an amended and restated debt commitment letter with Barclays and both Bank of America, N.A. and Merrill Lynch, Pierce, Fenner & Smith Incorporated (together, "BAML"). Pursuant to the commitment letter, among other things, Barclays and BAML have committed to provide us with debt financing in an aggregate principal amount of up to $850.0 million to finance the acquisition of Rofin. The obligations of Barclays and BAML under the commitment letter are subject to certain conditions, including the consummation of the acquisition in accordance with the terms and conditions of the definitive agreement and other customary closing obligations. For our $850.0 million debt financing commitment with Barclays and BAML, we paid $2.1 million of debt issuance costs in the second quarter of fiscal 2016 and recorded it to other assets on our condensed consolidated balance sheets. The debt issuance cost will be reclassified when there is an outstanding debt.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Apr. 02, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION Fair Value of Stock Compensation We recognize compensation expense for all share based payment awards based on the fair value of such awards. The expense is recognized on a straight-line basis over the respective requisite service period of the awards. Determining Fair Value The fair values of shares purchased under the Employee Stock Purchase Plan (“ESPP”) for the three and six months ended April 2, 2016 and April 4, 2015 , respectively, were estimated using the following weighted-average assumptions: Employee Stock Purchase Plan Three Months Ended Six Months Ended April 2, April 4, April 2, April 4, Expected life in years 0.5 0.5 0.5 0.5 Expected volatility 26.0 % 24.8 % 27.4 % 24.8 % Risk-free interest rate 0.3 % 0.1 % 0.2 % 0.1 % Expected dividend yield — % — % — % — % Weighted average fair value per share $ 12.50 $ 14.26 $ 12.89 $ 14.11 There were no stock options granted during the three and six months ended April 2, 2016 and April 4, 2015 . We grant performance restricted stock units to officers and certain employees. The performance restricted stock unit agreements provide for the award of performance restricted stock units with each unit representing the right to receive one share of our common stock to be issued after the applicable award vesting period. The final number of units awarded, if any, for these performance grants will be determined as of the vesting dates, based upon our total shareholder return over the performance period compared to the Russell 2000 Index and could range from no units to a maximum of twice the initial award units. The weighted average fair value for these performance units was determined using a Monte Carlo simulation model incorporating the following weighted average assumptions: Six Months Ended April 2, 2016 April 4, 2015 Risk-free interest rate 1.20 % 0.96 % Volatility 27.0 % 28.7 % Weighted average fair value $ 74.48 $ 70.57 We recognize the estimated cost of these awards, as determined under the simulation model, over the related service period, with no adjustment in future periods based upon the actual shareholder return over the performance period. Stock-Based Compensation Expense The following table shows total stock-based compensation expense and related tax benefits included in the condensed consolidated statements of operations for the three and six months ended April 2, 2016 and April 4, 2015 (in thousands): Three Months Ended Six Months Ended April 2, 2016 April 4, 2015 April 2, 2016 April 4, 2015 Cost of sales $ 594 $ 676 $ 1,199 $ 1,273 Research and development 610 556 1,036 886 Selling, general and administrative 4,183 3,550 6,897 7,013 Income tax benefit (1,511 ) (1,303 ) (1,862 ) (1,733 ) $ 3,876 $ 3,479 $ 7,270 $ 7,439 During the three and six months ended April 2, 2016 , $0.7 million and $1.3 million was capitalized into inventory for all stock plans, $0.6 million and $1.2 million was amortized to cost of sales and $0.8 million remained in inventory at April 2, 2016 . During the three and six months ended April 4, 2015 , $0.7 million and $1.4 million was capitalized into inventory for all stock plans, $0.7 million and $1.3 million was amortized to cost of sales and $0.8 million remained in inventory at April 4, 2015 . At April 2, 2016 , the total compensation cost related to unvested stock-based awards granted to employees under the Company’s stock plans but not yet recognized was approximately $31.0 million , net of estimated forfeitures of $1.4 million . This cost will be amortized on a straight-line basis over a weighted-average period of approximately 1.6 years and will be adjusted for subsequent changes in estimated forfeitures. At April 2, 2016 , total compensation cost related to options to purchase common shares under the ESPP but not yet vested was approximately $0.1 million , which will be recognized over the six month offering period. Stock Awards Activity The following table summarizes the activity of our time-based and performance restricted stock units for the first six months of fiscal 2016 (in thousands, except per share amounts): Time Based Restricted Stock Units Market-Based Performance Restricted Stock Units Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Nonvested stock units at October 3, 2015 394 $ 65.17 199 $ 67.09 Granted 269 64.30 65 74.48 Vested (1) (190 ) 61.15 (57 ) 48.48 Forfeited (11 ) 63.72 (38 ) 48.48 Nonvested stock at April 2, 2016 462 $ 66.35 169 $ 74.10 __________________________________________ (1) Service-based restricted stock vested during each fiscal year. Performance-based awards and units included at 100% of target goal; under the terms of the awards, the recipient may earn between 0% and 200% of the award.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Apr. 02, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES We are subject to legal claims and litigation arising in the ordinary course of business, such as product liability, employment or intellectual property claims, including, but not limited to, the matters described below. On May 14, 2013, IMRA America (“Imra”) filed a complaint for patent infringement against two of our subsidiaries in the Regional Court of Düsseldorf, Germany, captioned In re IMRA America Inc. versus Coherent Kaiserslautern GmbH et. al. 4b O 38/13. The complaint alleges that the use of certain of the Company’s lasers infringes upon EP Patent No. 754,103, entitled “Method For Controlling Configuration of Laser Induced Breakdown and Ablation,” issued November 5, 1997. The patent, now expired in all jurisdictions, is owned by the University of Michigan and licensed to Imra. The complaint seeks unspecified compensatory damages, the cost of court proceedings and seeks to permanently enjoin the Company from infringing the patent in the future. Following the filing of the infringement suit, our subsidiaries filed a separate nullity action with the Federal Patent Court in Munich, Germany requesting that the court hold that the Patent was invalid based on prior art. On October 1, 2015, the Federal Patent Court ruled that the German portion of the Patent was invalid. Imra has filed a notice to appeal this decision to the Federal Court of Justice, the highest civil jurisdiction court in Germany. The infringement action is currently stayed pending the outcome of such appeal. Management has made an accrual with respect to this matter and has determined, based on its current knowledge, that the amount or range of reasonably possible losses in excess of the amounts already accrued is not reasonably estimable. Although we do not expect that such legal claims and litigation will ultimately have a material adverse effect on our condensed consolidated financial position, results of operations or cash flows, an adverse result in one or more matters could negatively affect our results in the period in which they occur. The United States and many foreign governments impose tariffs and duties on the import and export of certain products we sell. From time to time our duty calculations and payments are audited by government agencies. During the second quarter of fiscal 2016, we concluded an audit in South Korea for customs duties and value added tax for the period March 2009 to March 2014. We paid $1.6 million related to this matter and have no remaining accrual at April 2, 2016 . On March 16, 2016, we entered into a debt commitment letter with Barclays Bank PLC ("Barclays") and on April 5, 2016, entered into an amended and restated debt commitment letter with Barclays and both Bank of America, N.A. and Merrill Lynch, Pierce, Fenner & Smith Incorporated (together, "BAML"). Pursuant to the commitment letter, among other things, Barclays and BAML have committed to provide us with debt financing in an aggregate principal amount of up to $850.0 million to finance the acquisition of Rofin. The obligations of Barclays and BAML under the commitment letter are subject to certain conditions, including the consummation of the acquisition in accordance with the terms and conditions of the definitive agreement and other customary closing obligations. For our $850.0 million debt financing commitment with Barclays and BAML, we paid $2.1 million of debt issuance costs in the second quarter of fiscal 2016 and recorded it to other assets on our condensed consolidated balance sheets. We have an agreement with a financial advisor, Barclays, in relation to the pending acquisition of Rofin. We have agreed to pay Barclays a fee of approximately $10.5 million , $1.0 million of which was paid upon delivery of the fairness opinion in the second quarter of fiscal 2016, and was recorded in the selling, general and administrative line of the condensed consolidated statements of operations, and the remaining portion of which will be paid upon, and subject to, consummation of the acquisition. We have also agreed to pay to Barclays approximately $17.0 million and $7.5 million for underwriting and upfront fees, respectively, upon the close of the financing. In addition, the acquisition agreement contains certain termination rights for Coherent and further provides that we may be required to pay a termination fee of $ 65.0 million to Rofin and $2.4 million to Barclays.

Stock Repurchase

Stock Repurchase	6 Months Ended
	Apr. 02, 2016
Stockholders' Equity Note [Abstract]
Stock Repurchase	STOCK REPURCHASE On July 25, 2014, the Board of Directors authorized a buyback program whereby we were authorized to repurchase up to $25.0 million of our common stock from time to time through July 31, 2015. During the first quarter of fiscal 2015, we repurchased and retired 300,441 shares of outstanding common stock at an average price of $57.55 per share for a total of $17.3 million , excluding expenses. During the second quarter of fiscal 2015, we repurchased and retired 133,673 shares of outstanding common stock under this plan at an average price of $57.66 per share for a total of $7.7 million , completing the repurchase program. On January 21, 2015, our Board of Directors authorized an additional stock repurchase program to repurchase up to $25.0 million of our outstanding common stock from time to time through January 31, 2016. During the fourth quarter of fiscal 2015, we repurchased and retired 430,675 shares of outstanding common stock under this plan at an average price of $58.05 per share for a total of $25.0 million . On August 25, 2015, our Board of Directors authorized an additional stock repurchase program to repurchase up to $25.0 million of our outstanding common stock from time to time through August 31, 2016. During the fourth quarter of fiscal 2015, we repurchased and retired 437,534 shares of outstanding common stock under this plan at an average price of $57.14 per share for a total of $25.0 million .

Earnings Per Share

Earnings Per Share	6 Months Ended
	Apr. 02, 2016
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE Basic earnings per share is computed based on the weighted average number of shares outstanding during the period, excluding unvested restricted stock. Diluted earnings per share is computed based on the weighted average number of shares outstanding during the period increased by the effect of dilutive employee stock awards, including stock options, restricted stock awards and stock purchase plan contracts, using the treasury stock method. The following table presents information necessary to calculate basic and diluted earnings per share (in thousands, except per share data): Three Months Ended Six Months Ended April 2, April 4, April 2, April 4, Weighted average shares outstanding —basic 24,137 24,709 24,066 24,823 Dilutive effect of employee stock awards 225 182 233 219 Weighted average shares outstanding—diluted 24,362 24,891 24,299 25,042 Net income $ 17,781 $ 18,413 $ 38,067 $ 35,843 Net income per basic share $ 0.74 $ 0.75 $ 1.58 $ 1.44 Net income per diluted share $ 0.73 $ 0.74 $ 1.57 $ 1.43 A total of 7,078 and 9,451 potentially dilutive securities have been excluded from the diluted share calculation for the three and six months ended April 2, 2016 as their effect was anti-dilutive. A total of 1,333 and 41,559 potentially dilutive securities have been excluded from the diluted share calculation for the three and six months ended April 4, 2015 as their effect was anti-dilutive.

Other Income (Expense)

Other Income (Expense)	6 Months Ended
	Apr. 02, 2016
Other Income and Expenses [Abstract]
Other Income (Expense)	14. OTHER INCOME (EXPENSE) Other income (expense) is as follows (in thousands): Three Months Ended Six Months Ended April 2, April 4, April 2, April 4, Foreign exchange gain (loss) $ (198 ) $ 1,080 $ (1,520 ) $ (81 ) Gain (loss) on deferred compensation investments, net (1,877 ) 671 (1,002 ) 1,055 Other 62 92 62 99 Other - net $ (2,013 ) $ 1,843 $ (2,460 ) $ 1,073

Income Taxes

Income Taxes	6 Months Ended
	Apr. 02, 2016
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Income tax expense includes a provision for federal, state and foreign taxes based on the annual estimated effective tax rate applicable to us and our subsidiaries, adjusted for items which are considered discrete to the period. Our effective tax rates for the three and six months ended April 2, 2016 were 26.6% and 25.8% , respectively. Our effective tax rates for the three and six months ended April 2, 2016 were lower than the statutory rate of 35.0% primarily due to differences related to the benefit of income subject to foreign tax rates that are lower than U.S. tax rates including the Singapore tax exemption, the benefit of foreign tax credits and the benefit of federal research and development tax credits including renewal of the federal research and development tax credits for fiscal 2015. These amounts are partially offset by deemed dividend inclusions under the Subpart F tax rules, stock-based compensation not deductible for tax purposes and limitations on the deductibility of compensation under IRC Section 162(m). Our effective tax rates for the three and six months ended April 4, 2015 were 23.7% and 24.9% , respectively. Our effective tax rates for the three and six months ended April 4, 2015 were lower than the statutory rate of 35.0% primarily due to differences related to the benefit of income subject to foreign tax rates that are lower than U.S. statutory tax rates including South Korea and Singapore tax exemptions, the benefit of foreign tax credits and the benefit of the federal research and development tax credits including renewal of the federal research and development tax credits for fiscal 2014. These amounts are partially offset by deemed dividend inclusions under the Subpart F tax rules, stock-based compensation not deductible for tax purposes and limitations on the deductibility of compensation under IRC Section 162(m). Determining the consolidated provision for income taxes, income tax liabilities and deferred tax assets and liabilities involves judgment. We calculate and provide for income taxes in each of the tax jurisdictions in which we operate, which involves estimating current tax exposures as well as making judgments regarding the recoverability of deferred tax assets in each jurisdiction. The estimates used could differ from actual results, which may have a significant impact on operating results in future periods. We are subject to taxation and file income tax returns in the U.S. federal jurisdiction and in many state and foreign jurisdictions. For U.S. federal income tax purposes, all years prior to 2011 are closed. In our major foreign jurisdictions and our major state jurisdictions, the years prior to 2006 and 2011, respectively, are closed to examination. Earlier years in our various jurisdictions may remain open for adjustment to the extent that we have tax attribute carryforwards from those years. In March 2016, the Internal Revenue Service (IRS) issued an audit notice and Information Documentation Requests (IDRs) for fiscal year 2013. We have responded to the IDRs and the IRS field work will begin soon. In December 2011 and January 2012, three of our German subsidiaries received notices of tax audits for the fiscal years 2006 through 2010. In fiscal year 2013, we received a preliminary assessment for two of the German subsidiaries and the amount is immaterial. In September 2015, the German tax authorities issued preliminary tax findings for Coherent GmbH for the years 2006 to 2010 and Coherent management met with the German tax authorities in December 2015 to discuss the preliminary assessments. Coherent Management anticipates that the German tax authorities will issue the final audit assessment in the third quarter of fiscal 2016. In July 2015 and March 2016, Coherent Kaiserslautern GmbH (formerly Lumera Laser GmbH) received tax audit notices for the years 2010 to 2014. The audit began in August 2015. We acquired the shares of Lumera Laser GmbH in December 2012 and we should not have responsibility for any assessments related to the pre-acquisition period. In March 2016, Coherent Japan KK received a tax audit notice for the years 2013 to 2015. The audit will begin in July 2016. Management believes that it has adequately provided reserves for any adjustments that may result from tax examinations. We regularly engage in discussions and negotiations with tax authorities regarding tax matters in various jurisdictions. It is reasonably possible that certain federal, foreign and state tax matters may be concluded in the next 12 months. The Consolidated Appropriations Act of 2016 (“the Act”), was enacted on December 18, 2015. Under the Act, the federal research and development tax credit was retroactively extended for amounts paid or incurred after December 31, 2014 through December 31, 2015 and the credit was made permanent. The effects of the change in the tax law are recognized in our first quarter of fiscal 2016, which is the quarter that the law was enacted. Accordingly, prior year research and development tax credits of approximately $1.2 million , after netting with appropriate reserves, were recognized in the first quarter of fiscal 2016. Coherent Korea received approval for an additional High-Tech tax exemption in April 2016 from the Korean authorities and must make a capital contribution for the exemption to be effective. We anticipate making a capital contribution of approximately $4.0 million by the end of fiscal year 2016.

Segment Information

Segment Information	6 Months Ended
	Apr. 02, 2016
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION The following table provides net sales and income from operations for our operating segments and a reconciliation of our total income from operations to net income (in thousands): Three Months Ended Six Months Ended April 2, April 4, April 2, April 4, Net sales: Specialty Laser Systems $ 143,353 $ 140,016 $ 279,304 $ 285,107 Commercial Lasers and Components 56,529 63,705 110,853 119,229 Total net sales $ 199,882 $ 203,721 $ 390,157 $ 404,336 Income(expense) from operations: Specialty Laser Systems $ 37,635 $ 32,078 $ 73,430 $ 66,632 Commercial Lasers and Components 1,584 2,279 3,399 2,982 Corporate and other (13,215 ) (12,225 ) (23,542 ) (23,173 ) Total income from operations $ 26,004 $ 22,132 $ 53,287 $ 46,441 Total other income (expense), net (1,780 ) 1,990 (2,002 ) 1,305 Income before income taxes 24,224 24,122 51,285 47,746 Provision for income taxes 6,443 5,709 13,218 11,903 Net Income $ 17,781 $ 18,413 $ 38,067 $ 35,843 Major Customers We had one major customer during the three and six months ended April 2, 2016 who accounted for 17.3% and 17.5% , respectively, of consolidated revenue. This same customer accounted for 17.4% and 18.0% , respectively, of consolidated revenue for the three and six months ended April 4, 2015 . We had another major customer during the six months ended April 2, 2016 who accounted for 10.2% of consolidated revenue. These customers purchased primarily from our SLS segment. We had one major customer who accounted for 19.3% of accounts receivable at April 2, 2016 . We had another major customer who accounted for 15.3% and 21.4% of accounts receivable at April 2, 2016 and October 3, 2015 , respectively. Both customers purchased primarily from our SLS segment.

Business Combinations (Tables)

Business Combinations (Tables)	6 Months Ended
	Apr. 02, 2016
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	Our allocation of the purchase price is as follows (in thousands): Tangible assets: Inventories $ 2,240 Accounts receivable 2,263 Prepaid expenses and other assets 1,132 Property and equipment 2,451 Liabilities assumed (1,702 ) Deferred tax liabilities (768 ) Gain on business combination (1,316 ) Total $ 4,300 Our allocation of the purchase price is as follows (in thousands): Tangible assets $ 1,048 Goodwill 1,552 Intangible assets: Existing technology 800 Customer lists 1,600 Total $ 5,000

Fair Values (Tables)

Fair Values (Tables)	6 Months Ended
	Apr. 02, 2016
Fair Value Disclosures [Abstract]
Schedule of financial assets and liabilities measured at fair value	Financial assets and liabilities measured at fair value as of April 2, 2016 and October 3, 2015 are summarized below (in thousands): Aggregate Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Aggregate Fair Value Quoted Prices Significant Other Observable Inputs April 2, 2016 October 3, 2015 (Level 1) (Level 2) (Level 1) (Level 2) Assets: Cash equivalents: Money market fund deposits $ 32,184 $ 32,184 $ — $ 8,297 $ 8,297 $ — Short-term investments: U.S. Treasury and agency obligations (2) $ 140,766 $ — $ 140,766 $ 150,748 $ — $ 150,748 Corporate notes and obligations (2) 35,190 — 35,190 17,942 — 17,942 Commercial paper (2) 7,464 — 7,464 9,740 — 9,740 Equity securities (1) 20,462 20,462 — 16,478 16,478 — Prepaid and other assets: Foreign currency contracts (3) 3,152 — 3,152 258 — 258 Mutual funds — Deferred comp and supplemental plan (4) 12,301 12,301 — 13,891 13,891 — Total $ 251,519 $ 64,947 $ 186,572 $ 217,354 $ 38,666 $ 178,688 Liabilities: Other current liabilities: Foreign currency contracts (3) $ (1,904 ) $ — $ (1,904 ) $ (239 ) $ — $ (239 ) Total $ 249,615 $ 64,947 $ 184,668 $ 217,115 $ 38,666 $ 178,449 ___________________________________________________ (1) Valuations are based upon quoted market prices. (2) Valuations are based upon quoted market prices in active markets involving similar assets. The market inputs used to value these instruments generally consist of market yields, reported trades, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. Pricing sources include industry standard data providers, security master files from large financial institutions, and other third party sources which are input into a distribution-curve-based algorithm to determine a daily market value. This creates a “consensus price” or a weighted average price for each security. (3) The principal market in which we execute our foreign currency contracts is the institutional market in an over-the-counter environment with a relatively high level of price transparency. The market participants usually are large commercial banks. Our foreign currency contracts’ valuation inputs are based on quoted prices and quoted pricing intervals from public data sources and do not involve management judgment. At April 2, 2016 , prepaid expenses and other assets include $3,152 non-designated forward contracts; other current liabilities include $1,904 non-designated forward contracts. At October 3, 2015 , prepaid expenses and other assets include $217 non-designated forward contracts and $41 foreign currency contracts designated for cash flow hedges, respectively; other current liabilities include $239 non-designated forward contracts and $0 foreign currency contracts designated for cash flow hedges respectively. See Note 6, "Derivative Instruments and Hedging Activities". (4) The fair value of mutual funds is determined based on quoted market prices. Securities traded on a national exchange are stated at the last reported sales price on the day of valuation; other securities traded in over-the-counter markets and listed securities for which no sale was reported on that date are stated as the last quoted bid price.

Short-Term Investments (Tables)

Short-Term Investments (Tables)	6 Months Ended
	Apr. 02, 2016
Cash, Cash Equivalents, and Short-term Investments [Abstract]
Schedule of cash, cash equivalents and short-term investments	Cash, cash equivalents and short-term investments consist of the following (in thousands): April 2, 2016 Cost Basis Unrealized Gains Unrealized Losses Fair Value Cash and cash equivalents $ 157,176 $ — $ — $ 157,176 Short-term investments: Available-for-sale securities: Commercial paper $ 7,464 $ — $ — $ 7,464 U.S. Treasury and agency obligations 139,943 854 (31 ) 140,766 Corporate notes and obligations 35,093 104 (7 ) 35,190 Equity Securities 15,269 5,193 — 20,462 Total short-term investments $ 197,769 $ 6,151 $ (38 ) $ 203,882 October 3, 2015 Cost Basis Unrealized Gains Unrealized Losses Fair Value Cash and cash equivalents $ 130,607 $ — $ — $ 130,607 Short-term investments: Available-for-sale securities: Commercial paper $ 9,740 $ — $ — $ 9,740 U.S. Treasury and agency obligations 149,708 1,040 — 150,748 Corporate notes and obligations 17,892 52 (2 ) 17,942 Equity securities 15,269 1,209 — 16,478 Total short-term investments $ 192,609 $ 2,301 $ (2 ) $ 194,908
Schedule of amortized cost and estimated fair value of available-for-sale investments in debt securities	The amortized cost and estimated fair value of available-for-sale investments in debt securities as of April 2, 2016 and October 3, 2015 classified as short-term investments on our condensed consolidated balance sheet were as follows (in thousands): April 2, 2016 October 3, 2015 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Investments in available-for-sale debt securities due in less than one year $ 163,210 $ 164,061 $ 148,088 $ 149,100 Investments in available-for-sale debt securities due in one to five years (1) $ 19,290 $ 19,359 $ 29,252 $ 29,330

Derivative Instruments and He27

Derivative Instruments and Hedging Activities (Tables)	6 Months Ended
	Apr. 02, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of outstanding notional contract and fair value amount of hedge contracts	The outstanding notional contract and fair value asset (liability) amounts of non-designated hedge contracts, with maximum maturity of two months, are as follows (in thousands): U.S. Notional Contract Value U.S. Fair Value April 2, 2016 October 3, 2015 April 2, 2016 October 3, 2015 Euro currency hedge contracts Purchase $ 63,507 $ 52,699 $ 2,919 $ 33 Japanese Yen currency hedge contracts Purchase $ 2,000 $ 558 $ 66 $ 8 Sell $ (36,480 ) $ (15,804 ) $ (406 ) $ (84 ) South Korean Won currency hedge contracts Purchase $ — $ 253 $ — $ — Sell $ (15,872 ) $ (17,747 ) $ (1,154 ) $ 30 Chinese RMB currency hedge contracts Sell $ (10,538 ) $ (10,900 ) $ (193 ) $ (106 ) Other foreign currency hedge contracts Purchase $ 4,313 $ 3,283 $ 167 $ (49 ) Sell $ (2,070 ) $ (5,835 ) $ (151 ) $ 146 Designated Derivatives Cash flow hedges related to anticipated transactions are designated and documented at the inception of the hedge when we enter into contracts for specific future transactions. Cash flow hedges are evaluated for effectiveness quarterly. The effective portion of the gain or loss on these hedges is reported as a component of OCI in stockholder's equity and is reclassified into earnings when the underlying transaction affects earnings. We had no cash flow hedges outstanding at April 2, 2016 . Changes in the fair value of currency forward contracts due to changes in time value are excluded from the assessment of effectiveness and recognized in other income (expense) as incurred. We classify the cash flows from the foreign exchange forward contracts that are accounted for as cash flow hedges in the same section as the underlying item, primarily within cash flows from operating activities since we do not designate our cash flow hedges as investing or financing activities. The outstanding notional contract and fair value asset (liability) amounts of designated cash flow hedge contracts, with maximum maturity of thirteen months, are as follows (in thousands): U.S. Notional Contract Value U.S. Fair Value April 2, 2016 October 3, 2015 April 2, 2016 October 3, 2015 Japanese Yen currency hedge contracts Sell $ — $ (2,093 ) $ — $ 41
Derivative Instruments, Gain (Loss)	The locations and amounts of designated and non-designated derivative instruments' gains and losses in the condensed consolidated financial statements for the indicated periods were as follows (in thousands): Location in financial statements Three Months Ended Six Months Ended April 2, 2016 April 4, 2015 April 2, 2016 April 4, 2015 Derivatives designated as hedging instruments Gains(losses) in OCI on derivatives (effective portion), after tax OCI $ 2 $ 175 $ (28 ) $ 550 Losses reclassified from OCI into income (effective portion) Cost of sales $ — $ (1,106 ) $ — $ (1,720 ) Gains(losses) reclassified from OCI into income (effective portion) Revenue $ (58 ) $ (92 ) $ (58 ) $ 208 Losses recognized in income on derivatives (ineffective portion and amount excluded from effectiveness testing) Other income(expense) $ (1 ) $ (77 ) $ (30 ) $ (112 ) Derivatives not designated as hedging instruments Losses recognized in income Other income(expense) $ (180 ) $ (5,413 ) $ (2,511 ) $ (6,125 )
Offsetting Assets	Offsetting of Financial Assets/Liabilities under Master Netting Agreements with Derivative Counterparties as of April 2, 2016 and October 3, 2015 (in thousands): Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets Gross Amounts of Recognized Derivative Assets Gross Amounts Offset in the Condensed Consolidated Balance Sheets Net Amounts of Derivative Assets Presented in the Condensed Consolidated Balance Sheets Financial Instruments (1) Cash Collateral Received Net Amounts As of April 2, 2016: Foreign exchange contracts $ 3,152 $ — $ 3,152 $ (1,186 ) $ — $ 1,966 As of October 3, 2015: Foreign exchange contracts $ 258 $ — $ 258 $ (116 ) $ — $ 142 (1) The balances at April 2, 2016 and October 3, 2015 were related to derivative liabilities which are allowed to be net settled against derivative assets in accordance with the master netting agreements.
Offsetting Liabilities	Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets Gross Amounts of Recognized Derivative Liabilities Gross Amounts Offset in the Condensed Consolidated Balance Sheets Net Amounts of Derivative Liabilities Presented in the Condensed Consolidated Balance Sheets Financial Instruments (1) Cash Collateral Paid Net Amounts As of April 2, 2016: Foreign exchange contracts $ (1,904 ) $ — $ (1,904 ) $ 1,186 $ — $ (718 ) As of October 3, 2015: Foreign exchange contracts $ (239 ) $ — $ (239 ) $ 116 $ — $ (123 ) (1) The balances at April 2, 2016 and October 3, 2015 were related to derivative assets which are allowed to be net settled against derivative liabilities in accordance with the master netting agreements.

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Apr. 02, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes in carrying amount of goodwill by segment	The changes in the carrying amount of goodwill by segment for the period from October 3, 2015 to April 2, 2016 are as follows (in thousands): Specialty Lasers and Systems Commercial Lasers and Components Total Balance as of October 3, 2015 $ 95,454 $ 6,363 $ 101,817 Translation adjustments and other 1,059 — 1,059 Balance as of April 2,2016 $ 96,513 $ 6,363 $ 102,876
Schedule of components of amortizable intangible assets	Components of our amortizable intangible assets are as follows (in thousands): April 2, 2016 October 3, 2015 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Existing technology $ 71,384 $ (58,701 ) $ 12,683 $ 71,365 $ (55,452 ) $ 15,913 Customer lists 16,141 (10,733 ) 5,408 16,099 (9,661 ) 6,438 Trade name 393 (353 ) 40 399 (349 ) 50 In-process research & development 379 — 379 375 — 375 Total $ 88,297 $ (69,787 ) $ 18,510 $ 88,238 $ (65,462 ) $ 22,776 For accounting purposes, when an intangible asset is fully amortized, it is removed from the disclosure schedule. Amortization expense for intangible assets for the six months ended April 2, 2016 and April 4, 2015 was $4.2 million and $4.2 million , respectively, which includes $3.1 million and $3.3 million , respectively, for amortization of existing technology.
Schedule of estimated amortization expense	At April 2, 2016 , estimated amortization expense for the remainder of fiscal 2016 , the next five succeeding fiscal years and all fiscal years thereafter are as follows (in thousands): Estimated Amortization Expense 2016 (remainder) $ 3,925 2017 7,136 2018 4,362 2019 2,228 2020 696 2021 54 Thereafter 109 Total $ 18,510

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	6 Months Ended
	Apr. 02, 2016
Balance Sheet Related Disclosures [Abstract]
Schedule of inventories	Inventories consist of the following (in thousands): April 2, October 3, Purchased parts and assemblies $ 54,339 $ 50,182 Work-in-process 70,632 56,225 Finished goods 54,096 50,207 Total inventories $ 179,067 $ 156,614
Schedule of prepaid expenses and other assets	Prepaid expenses and other assets consist of the following (in thousands): April 2, October 3, Prepaid and refundable income taxes $ 9,880 $ 8,846 Other taxes receivable 7,177 6,574 Prepaid expenses and other assets 17,545 12,874 Total prepaid expenses and other assets $ 34,602 $ 28,294
Schedule of other assets	Other assets consist of the following (in thousands): April 2, October 3, Assets related to deferred compensation arrangements $ 23,352 $ 25,131 Deferred tax assets 64,027 60,254 Other assets 6,067 3,841 Total other assets $ 93,446 $ 89,226
Schedule of Other Current Liabilities	Other current liabilities consist of the following (in thousands): April 2, October 3, Accrued payroll and benefits $ 37,706 $ 35,504 Deferred revenue 17,772 16,474 Warranty reserve 14,972 15,308 Accrued expenses and other 11,908 10,965 Other taxes payable 5,586 4,888 Customer deposits 1,864 1,793 Total other current liabilities $ 89,808 $ 84,932
Schedule of components of reserve for warranty costs	Components of the reserve for warranty costs during the first six months of fiscal 2016 and 2015 were as follows (in thousands): Six Months Ended April 2, April 4, Beginning balance $ 15,308 $ 16,961 Additions related to current period sales 10,412 11,618 Warranty costs incurred in the current period (10,693 ) (10,822 ) Adjustments to accruals related to foreign exchange and other (55 ) (1,816 ) Ending balance $ 14,972 $ 15,941
Schedule of Other Long-term liabilities	Other long-term liabilities consist of the following (in thousands): April 2, October 3, Long-term taxes payable $ 7,823 $ 7,651 Deferred compensation 24,938 26,691 Deferred tax liabilities 2,259 2,717 Deferred income 3,722 3,149 Asset retirement obligations liability 2,726 2,654 Other long-term liabilities 7,715 7,077 Total other long-term liabilities $ 49,183 $ 49,939

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Apr. 02, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of weighted-average assumptions used to estimate fair value of stock options granted and shares purchased	The fair values of shares purchased under the Employee Stock Purchase Plan (“ESPP”) for the three and six months ended April 2, 2016 and April 4, 2015 , respectively, were estimated using the following weighted-average assumptions: Employee Stock Purchase Plan Three Months Ended Six Months Ended April 2, April 4, April 2, April 4, Expected life in years 0.5 0.5 0.5 0.5 Expected volatility 26.0 % 24.8 % 27.4 % 24.8 % Risk-free interest rate 0.3 % 0.1 % 0.2 % 0.1 % Expected dividend yield — % — % — % — % Weighted average fair value per share $ 12.50 $ 14.26 $ 12.89 $ 14.11
Schedule of weighted average assumptions of performance units	The weighted average fair value for these performance units was determined using a Monte Carlo simulation model incorporating the following weighted average assumptions: Six Months Ended April 2, 2016 April 4, 2015 Risk-free interest rate 1.20 % 0.96 % Volatility 27.0 % 28.7 % Weighted average fair value $ 74.48 $ 70.57
Schedule of stock-based compensation expense	The following table shows total stock-based compensation expense and related tax benefits included in the condensed consolidated statements of operations for the three and six months ended April 2, 2016 and April 4, 2015 (in thousands): Three Months Ended Six Months Ended April 2, 2016 April 4, 2015 April 2, 2016 April 4, 2015 Cost of sales $ 594 $ 676 $ 1,199 $ 1,273 Research and development 610 556 1,036 886 Selling, general and administrative 4,183 3,550 6,897 7,013 Income tax benefit (1,511 ) (1,303 ) (1,862 ) (1,733 ) $ 3,876 $ 3,479 $ 7,270 $ 7,439
Schedule of restricted stock award and restricted stock unit activity	The following table summarizes the activity of our time-based and performance restricted stock units for the first six months of fiscal 2016 (in thousands, except per share amounts): Time Based Restricted Stock Units Market-Based Performance Restricted Stock Units Number of Shares Weighted Average Grant Date Fair Value Number of Shares Weighted Nonvested stock units at October 3, 2015 394 $ 65.17 199 $ 67.09 Granted 269 64.30 65 74.48 Vested (1) (190 ) 61.15 (57 ) 48.48 Forfeited (11 ) 63.72 (38 ) 48.48 Nonvested stock at April 2, 2016 462 $ 66.35 169 $ 74.10 __________________________________________ (1) Service-based restricted stock vested during each fiscal year. Performance-based awards and units included at 100% of target goal; under the terms of the awards, the recipient may earn between 0% and 200% of the award.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Apr. 02, 2016
Earnings Per Share [Abstract]
Schedule of information necessary to calculate basic and diluted earnings (loss) per share	The following table presents information necessary to calculate basic and diluted earnings per share (in thousands, except per share data): Three Months Ended Six Months Ended April 2, April 4, April 2, April 4, Weighted average shares outstanding —basic 24,137 24,709 24,066 24,823 Dilutive effect of employee stock awards 225 182 233 219 Weighted average shares outstanding—diluted 24,362 24,891 24,299 25,042 Net income $ 17,781 $ 18,413 $ 38,067 $ 35,843 Net income per basic share $ 0.74 $ 0.75 $ 1.58 $ 1.44 Net income per diluted share $ 0.73 $ 0.74 $ 1.57 $ 1.43

Other Income (Expense) (Tables)

Other Income (Expense) (Tables)	6 Months Ended
	Apr. 02, 2016
Other Income and Expenses [Abstract]
Schedule of other nonoperating income (expense)	Other income (expense) is as follows (in thousands): Three Months Ended Six Months Ended April 2, April 4, April 2, April 4, Foreign exchange gain (loss) $ (198 ) $ 1,080 $ (1,520 ) $ (81 ) Gain (loss) on deferred compensation investments, net (1,877 ) 671 (1,002 ) 1,055 Other 62 92 62 99 Other - net $ (2,013 ) $ 1,843 $ (2,460 ) $ 1,073

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Apr. 02, 2016
Segment Reporting [Abstract]
Schedule of sales and income (loss) from operations	The following table provides net sales and income from operations for our operating segments and a reconciliation of our total income from operations to net income (in thousands): Three Months Ended Six Months Ended April 2, April 4, April 2, April 4, Net sales: Specialty Laser Systems $ 143,353 $ 140,016 $ 279,304 $ 285,107 Commercial Lasers and Components 56,529 63,705 110,853 119,229 Total net sales $ 199,882 $ 203,721 $ 390,157 $ 404,336 Income(expense) from operations: Specialty Laser Systems $ 37,635 $ 32,078 $ 73,430 $ 66,632 Commercial Lasers and Components 1,584 2,279 3,399 2,982 Corporate and other (13,215 ) (12,225 ) (23,542 ) (23,173 ) Total income from operations $ 26,004 $ 22,132 $ 53,287 $ 46,441 Total other income (expense), net (1,780 ) 1,990 (2,002 ) 1,305 Income before income taxes 24,224 24,122 51,285 47,746 Provision for income taxes 6,443 5,709 13,218 11,903 Net Income $ 17,781 $ 18,413 $ 38,067 $ 35,843

Basis of Presentation (Details)

Basis of Presentation (Details) $ in Millions	Oct. 03, 2015USD ($)
New Accounting Pronouncement, Early Adoption, Effect [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Deferred Tax Assets, Net, Current	$ 28.1

Recent Accounting Standards (De

Recent Accounting Standards (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Apr. 02, 2016	Apr. 02, 2016	Apr. 04, 2015	Oct. 03, 2015
Item Effected [Line Items]
Debt Issuance Costs		$ 2,137	$ 0
New Accounting Pronouncement, Early Adoption, Effect [Member]
Item Effected [Line Items]
Deferred Tax Assets, Net, Current				$ 28,100
Debt Issuance Costs	$ 2,137

Business Combinations (Details)

Business Combinations (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 16, 2016	Jul. 27, 2015	Jul. 24, 2015	Oct. 03, 2015	Oct. 03, 2015	Apr. 02, 2016
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tangible Assets			$ 1,048
Goodwill				$ 101,817	$ 101,817	$ 102,876
Rofin-Sinar [Member]
Business Acquisition [Line Items]
All-cash transaction at a price per share of target	$ 32.50
Payments to Acquire Businesses, Gross	$ 942,000
Raydianceinc [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross			5,000
Goodwill			1,552
Goodwill, Period Increase					400
Tangible assets, Period Decrease					400
Business Combination, Acquisition Related Costs					100
Tinsley [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross		$ 4,300
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory		2,240
Business Combination, Acquisition Related Costs					$ 400
Business Combination, Acquired Receivables, Gross Contractual Amount		2,263
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets		1,132
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment		2,451
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		(1,702)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent		(768)
Business Combination, Bargain Purchase, Gain Recognized, Amount		$ (1,316)
Minimum [Member] | Raydianceinc [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life				3 years
Maximum [Member] | Raydianceinc [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life				5 years
Existing technology | Raydianceinc [Member]
Business Acquisition [Line Items]
Goodwill, Acquired During Period			800
Customer lists | Raydianceinc [Member]
Business Acquisition [Line Items]
Goodwill, Acquired During Period			$ 1,600

Fair Values (Details)

Fair Values (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands		Apr. 02, 2016	Oct. 03, 2015
Quoted Prices in Active Markets for Identical Assets (Level 1) | Supplemental Employee Retirement Plans, Defined Benefit | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	[1]	$ 12,301	$ 13,891
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market fund deposits | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		32,184	8,297
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. and international government obligations | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate notes and obligations | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial Paper [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[2]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity Securities [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	20,462	16,478
Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign Exchange Contract [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Foreign currency contracts	[4]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Foreign currency contracts	[4]	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Financial Assets, Balance Sheet Location [Member] | Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		64,947	38,666
Quoted Prices in Active Markets for Identical Assets (Level 1) | Financial Assets, Balance Sheet Location [Member] | Other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		64,947	38,666
Significant Other Observable Inputs (Level 2) | Supplemental Employee Retirement Plans, Defined Benefit | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	[1]	0	0
Significant Other Observable Inputs (Level 2) | Foreign Exchange Forward [Member] | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value		3,152	217
Significant Other Observable Inputs (Level 2) | Foreign Exchange Forward [Member] | Other Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value		1,904	239
Significant Other Observable Inputs (Level 2) | Cash Flow Hedging [Member] | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value			41
Significant Other Observable Inputs (Level 2) | Cash Flow Hedging [Member] | Other Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value			0
Significant Other Observable Inputs (Level 2) | Money market fund deposits | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		0	0
Significant Other Observable Inputs (Level 2) | U.S. and international government obligations | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[2]	140,766	150,748
Significant Other Observable Inputs (Level 2) | Corporate notes and obligations | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[2]	35,190	17,942
Significant Other Observable Inputs (Level 2) | Commercial Paper [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[2]	7,464	9,740
Significant Other Observable Inputs (Level 2) | Equity Securities [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	0	0
Significant Other Observable Inputs (Level 2) | Foreign Exchange Contract [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Foreign currency contracts	[4]	(1,904)	(239)
Significant Other Observable Inputs (Level 2) | Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Foreign currency contracts	[4]	3,152	258
Significant Other Observable Inputs (Level 2) | Financial Assets, Balance Sheet Location [Member] | Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		186,572	178,688
Significant Other Observable Inputs (Level 2) | Financial Assets, Balance Sheet Location [Member] | Other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		184,668	178,449
Total Fair Value | Supplemental Employee Retirement Plans, Defined Benefit | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	[1]	12,301	13,891
Total Fair Value | Money market fund deposits | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		32,184	8,297
Total Fair Value | U.S. and international government obligations | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[2]	140,766	150,748
Total Fair Value | Corporate notes and obligations | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[2]	35,190	17,942
Total Fair Value | Commercial Paper [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[2]	7,464	9,740
Total Fair Value | Equity Securities [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	[3]	20,462	16,478
Total Fair Value | Foreign Exchange Contract [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Foreign currency contracts	[4]	(1,904)	(239)
Total Fair Value | Foreign Exchange Contract [Member] | Prepaid Expenses and Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Foreign currency contracts	[4]	3,152	258
Total Fair Value | Financial Assets, Balance Sheet Location [Member] | Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		251,519	217,354
Total Fair Value | Financial Assets, Balance Sheet Location [Member] | Other current liabilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Financial assets and liabilities, fair value disclosure		$ 249,615	$ 217,115
[1]	The fair value of mutual funds is determined based on quoted market prices. Securities traded on a national exchange are stated at the last reported sales price on the day of valuation; other securities traded in over-the-counter markets and listed securities for which no sale was reported on that date are stated as the last quoted bid price.
[2]	Valuations are based upon quoted market prices in active markets involving similar assets. The market inputs used to value these instruments generally consist of market yields, reported trades, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. Pricing sources include industry standard data providers, security master files from large financial institutions, and other third party sources which are input into a distribution-curve-based algorithm to determine a daily market value. This creates a “consensus price” or a weighted average price for each security.
[3]	Valuations are based upon quoted market prices.
[4]	The principal market in which we execute our foreign currency contracts is the institutional market in an over-the-counter environment with a relatively high level of price transparency. The market participants usually are large commercial banks. Our foreign currency contracts’ valuation inputs are based on quoted prices and quoted pricing intervals from public data sources and do not involve management judgment. At April 2, 2016, prepaid expenses and other assets include $3,152 non-designated forward contracts; other current liabilities include $1,904 non-designated forward contracts. At October 3, 2015, prepaid expenses and other assets include $217 non-designated forward contracts and $41 foreign currency contracts designated for cash flow hedges, respectively; other current liabilities include $239 non-designated forward contracts and $0 foreign currency contracts designated for cash flow hedges respectively. See Note 6, "Derivative Instruments and Hedging Activities".

Short-Term Investments (Details

Short-Term Investments (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Apr. 02, 2016	Apr. 04, 2015	Apr. 02, 2016	Apr. 04, 2015	Oct. 03, 2015
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Cash and cash equivalent, Cost Basis		$ 157,176		$ 157,176		$ 130,607
Cash and cash equivalent, Unrealized Gains		0		0		0
Cash and cash equivalent, Unrealized Losses		0		0		0
Cash and cash equivalent, Fair Value		157,176		157,176		130,607
Available-for-sale securities: Cost Basis		197,769		197,769		192,609
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments		6,151		6,151		2,301
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments		(38)		(38)		(2)
Available-for-sale securities: Fair Value		203,882		203,882		194,908
Available-for-sale Securities, Debt Maturities [Abstract]
Investments in available-for-sale debt securities due in less than one year, Amortized Cost		163,210		163,210		148,088
Investments in available-for-sale debt securities due in one to five years, Amortized Cost	[1]	19,290		19,290		29,252
Investments in available-for-sale debt securities due in less than one year, Estimated Fair Value		164,061		164,061		149,100
Investments in available-for-sale debt securities due in one to five years, Estimated Fair Value	[1]	19,359		19,359		29,330
Proceeds from sale of available-for-sale securities		13,500	$ 48,300	28,600	$ 77,800
Maximum [Member]
Available-for-sale Securities, Debt Maturities [Abstract]
Realized gross gains from sale of available-for-sale securities		100	$ 100	100	$ 100
Commercial Paper [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Available-for-sale securities: Cost Basis		7,464		7,464		9,740
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments		0		0		0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments		0		0		0
Available-for-sale securities: Fair Value		7,464		7,464		9,740
US Treasury and Government [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Available-for-sale securities: Cost Basis		139,943		139,943		149,708
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments		854		854		1,040
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments		(31)		(31)		0
Available-for-sale securities: Fair Value		140,766		140,766		150,748
Equity Securities [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Available-for-sale securities: Cost Basis		15,269		15,269		15,269
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments		5,193		5,193		1,209
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments		0		0		0
Available-for-sale securities: Fair Value		20,462		20,462		16,478
Corporate Note Securities [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Available-for-sale securities: Cost Basis		35,093		35,093		17,892
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments		104		104		52
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments		(7)		(7)		(2)
Available-for-sale securities: Fair Value		$ 35,190		$ 35,190		$ 17,942
[1]	(1) Classified as short-term investments because these securities are highly liquid and can be sold at any time.

Derivative Instruments and He39

Derivative Instruments and Hedging Activities (Notional and Fair Value) (Details) - USD ($) $ in Thousands	Apr. 02, 2016	Oct. 03, 2015
Purchase [Member] | Other Foreign Countries [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 4,313	$ 3,283
Derivative, Fair Value, Net	167	(49)
sell [Member] | Other Foreign Countries [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,070	5,835
Derivative, Fair Value, Net	(151)	146
Euro Member Countries, Euro | Purchase [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	63,507	52,699
Derivative, Fair Value, Net	2,919	33
Japan, Yen | Purchase [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2,000	558
Derivative, Fair Value, Net	66	8
Japan, Yen | sell [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	36,480	15,804
Derivative, Fair Value, Net	(406)	(84)
Japan, Yen | sell [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	0	2,093
Derivative, Fair Value, Net	0	41
Korea (South), Won | Purchase [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	0	253
Derivative, Fair Value, Net	0	0
Korea (South), Won | sell [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	15,872	17,747
Derivative, Fair Value, Net	(1,154)	30
China, Yuan Renminbi | sell [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	10,538	10,900
Derivative, Fair Value, Net	$ (193)	$ (106)

Derivative Instruments and He40

Derivative Instruments and Hedging Activities (Gain/Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 04, 2015	Mar. 29, 2014	Apr. 02, 2016	Apr. 04, 2015	Mar. 29, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Loss on Fair Value Hedge Ineffectiveness			$ 31	$ 106
Revenue, Net [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contracts	$ (58)	$ (92)		(58)	$ 208
Cost of Sales [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contracts	0	(1,106)		0	(1,720)
Other Income (Expense) [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contracts	(1)	(77)		(30)	(112)
Other Income (Expense) [Member] | Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contracts	(180)	(5,413)		(2,511)	(6,125)
Other Comprehensive Income (Loss) [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contracts	$ 2	$ 175		$ (28)	$ 550

Derivative Instruments and He41

Derivative Instruments and Hedging Activities (Offsetting of Financial Assets) (Details) - Foreign Exchange Contract [Member] - USD ($) $ in Thousands		Apr. 02, 2016	Oct. 03, 2015
Offsetting Assets [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 3,152	$ 258
Derivative Liability, Fair Value, Gross Liability		0	0
Net amounts of assets presented in balance sheets		3,152	258
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	[1]	(1,186)	(116)
Derivative, Collateral, Right to Reclaim Cash		0	0
Derivative asset, net amount		$ 1,966	$ 142
[1]	The balances at April 2, 2016 and October 3, 2015 were related to derivative liabilities which are allowed to be net settled against derivative assets in accordance with the master netting agreements.

Derivative Instruments and He42

Derivative Instruments and Hedging Activities (Offsetting of Financial Liabilities) (Details) - Foreign Exchange Contract [Member] - USD ($) $ in Thousands		Apr. 02, 2016	Oct. 03, 2015
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability		$ (1,904)	$ (239)
Derivative Asset, Fair Value, Gross Asset		0	0
Net amounts of liabilities presented in balance sheets		(1,904)	(239)
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	[1]	1,186	116
Derivative, Collateral, Obligation to Return Cash		0	0
Derivative liabilities, net amount		$ (718)	$ (123)
[1]	The balances at April 2, 2016 and October 3, 2015 were related to derivative assets which are allowed to be net settled against derivative liabilities in accordance with the master netting agreements.

Goodwill and Intangible Asset43

Goodwill and Intangible Assets (Goodwill) (Details) $ in Thousands	6 Months Ended
	Apr. 02, 2016USD ($)
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 101,817
Translation adjustments and other	1,059
Goodwill, end of period	102,876
Specialty Laser Systems
Goodwill [Roll Forward]
Goodwill, beginning of period	95,454
Translation adjustments and other	1,059
Goodwill, end of period	96,513
Commercial Lasers and Components
Goodwill [Roll Forward]
Goodwill, beginning of period	6,363
Translation adjustments and other	0
Goodwill, end of period	$ 6,363

Goodwill and Intangible Asset44

Goodwill and Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Thousands		6 Months Ended
		Apr. 02, 2016	Apr. 04, 2015	Oct. 03, 2015
Finite-Lived Intangible Assets, Net [Abstract]
Intangible Assets, Gross Carrying Amount	[1]	$ 88,297		$ 88,238
Intangible Assets, Accumulated Amortization	[1]	(69,787)		(65,462)
Intangible Assets, Net	[1]	18,510		22,776
Amortization expense for intangible assets		4,169	$ 4,216
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
2016 (remainder)		3,925
2,017		7,136
2,018		4,362
2,019		2,228
2,020		696
2,021		54
Thereafter		109
Intangible Assets, Net	[1]	18,510		22,776
foreign exchange impact on accumulated amortization of intangible assets		100	3,500
Existing Technology and Production Know-how [Member]
Finite-Lived Intangible Assets, Net [Abstract]
Amortization expense for intangible assets		3,100	$ 3,300
Existing technology
Finite-Lived Intangible Assets, Net [Abstract]
Intangible Assets, Gross Carrying Amount		71,384		71,365
Intangible Assets, Accumulated Amortization		(58,701)		(55,452)
Intangible Assets, Net		12,683		15,913
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Intangible Assets, Net		12,683		15,913
Customer lists
Finite-Lived Intangible Assets, Net [Abstract]
Intangible Assets, Gross Carrying Amount		16,141		16,099
Intangible Assets, Accumulated Amortization		(10,733)		(9,661)
Intangible Assets, Net		5,408		6,438
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Intangible Assets, Net		5,408		6,438
Trade name
Finite-Lived Intangible Assets, Net [Abstract]
Intangible Assets, Gross Carrying Amount		393		399
Intangible Assets, Accumulated Amortization		(353)		(349)
Intangible Assets, Net		40		50
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Intangible Assets, Net		40		50
In-process research and development
Finite-Lived Intangible Assets, Net [Abstract]
Intangible Assets, Gross Carrying Amount		379		375
Intangible Assets, Accumulated Amortization		0		0
Intangible Assets, Net		379		375
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Intangible Assets, Net		$ 379		$ 375
[1]	For accounting purposes, when an intangible asset is fully amortized, it is removed from the disclosure schedule.

Balance Sheet Details (Details)

Balance Sheet Details (Details) - USD ($) $ in Thousands	6 Months Ended
	Apr. 02, 2016	Apr. 04, 2015	Oct. 03, 2015
Inventory, Net [Abstract]
Purchased parts and assemblies	$ 54,339		$ 50,182
Work-in-process	70,632		56,225
Finished goods	54,096		50,207
Total inventories	179,067		156,614
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid and refundable income taxes	9,880		8,846
Other Taxes Receivable	7,177		6,574
Prepaid expenses and other	17,545		12,874
Total prepaid expenses and other assets	34,602		28,294
Other Assets, Noncurrent Disclosure [Abstract]
Assets related to deferred compensation arrangements	23,352		25,131
Deferred tax assets	64,027		60,254
Other assets	6,067		3,841
Total other assets	93,446		89,226
Other Liabilities, Current [Abstract]
Accrued payroll and benefits	37,706		35,504
Deferred income	17,772		16,474
Warranty reserve	14,972		15,308
Accrued expenses and other	11,908		10,965
Other taxes payable	5,586		4,888
Customer deposits	1,864		1,793
Total other current liabilities	89,808		84,932
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Beginning balance	15,308	$ 16,961
Additions related to current period sales	10,412	11,618
Warranty costs incurred in the current period	(10,693)	(10,822)
Adjustments to accruals related to foreign exchange and other	(55)	(1,816)
Ending balance	14,972	$ 15,941
Other Liabilities, Noncurrent [Abstract]
Long-term taxes payable	7,823		7,651
Deferred compensation	24,938		26,691
Deferred tax liabilities	2,259		2,717
Deferred income	3,722		3,149
Asset retirement obligations	2,726		2,654
Other long-term liabilities	7,715		7,077
Total other long-term liabilities	49,183		$ 49,939
Line of Credit Facility, Maximum Borrowing Capacity	850,000
Debt Issuance Costs, Net	$ 2,137

Short-Term Borrowings (Details)

Short-Term Borrowings (Details) $ in Thousands	Apr. 02, 2016USD ($)
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 850,000
Debt Issuance Costs, Net	2,137
Line of Credit, Foreign
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	13,700
Amounts drawn upon line of credit	2,000
Line of Credit, Domestic
Line of Credit Facility [Line Items]
Domestic line of credit drawn	5,000
Domestic line of credit used	1,100
Line of Credit, Domestic | Union Bank of California, Unsecured Revolving Credit Account
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 50,000

Stock-Based Compensation (Fair

Stock-Based Compensation (Fair Value of Stock Compensation) (Details) - $ / shares	3 Months Ended		6 Months Ended
	Apr. 02, 2016	Apr. 04, 2015	Apr. 02, 2016	Apr. 04, 2015
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected life in years	6 months	6 months	6 months	6 months
Expected volatility	26.00%	24.80%	27.40%	24.80%
Risk-free interest rate	0.30%	0.10%	0.20%	0.10%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Weighted average fair value per share	$ 12.50	$ 14.26	$ 12.89	$ 14.11
Performance Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility			27.00%	28.70%
Risk-free interest rate			1.20%	0.96%
Weighted average fair value per share			$ 74.48	$ 70.57

Stock-Based Compensation (Stock

Stock-Based Compensation (Stock Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 02, 2016	Apr. 04, 2015	Apr. 02, 2016	Apr. 04, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures			0
Allocated stock-based compensation expense	$ (3,876)	$ (3,479)	$ (7,270)	$ (7,439)
Total stock-based compensation cost capitalized as part of inventory	700	700	1,300	1,400
Total stock-based compensation cost amortized into income	600	700	1,200	1,300
Total compensation cost, unvested stock-based awards granted but not yet recognized	31,000		31,000
Total compensation cost, unvested stock-based awards granted, but not yet recognized, forfeitures	1,400		$ 1,400
Total compensation cost, weighted-average period of amortization (in years)			1 year 7 months 12 days
Cost of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	(594)	(676)	$ (1,199)	(1,273)
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	(610)	(556)	(1,036)	(886)
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	(4,183)	(3,550)	(6,897)	(7,013)
Income tax benefit
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	(1,511)	$ (1,303)	(1,862)	(1,733)
Employee Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total compensation cost, unvested stock-based awards granted but not yet recognized	$ 100		$ 100
Total compensation cost, weighted-average period of amortization (in years)			6 months
PeriodEnd [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation cost capitalized as part of inventory			$ 800	$ 800

Stock-Based Compensation (Sto49

Stock-Based Compensation (Stock Options and Awards Activity) (Details)	6 Months Ended
	Apr. 02, 2016$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Granted, Number of Shares	0
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested stock, Number of Shares, beginning of period	394,000
Nonvested stock, Weighted Average Grant Date Fair Value, beginning of period | $ / shares	$ 65.17
Granted, Number of Shares	269,000
Granted, Weighted Average Grant Date Fair Value | $ / shares	$ 64.30
Vested, Number of Shares	(190,000)	[1]
Vested, Weighted Average Grant Date Fair Value | $ / shares	$ 61.15
Forfeited, Number of Shares	(11,000)
Forfeited, Weighted Average Grant Date Fair Value | $ / shares	$ 63.72
Nonvested stock, Number of Shares, end of period	462,000
Nonvested stock, Weighted Average Grant Date Fair Value, end of period | $ / shares	$ 66.35
Performance Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested stock, Number of Shares, beginning of period	199,000
Nonvested stock, Weighted Average Grant Date Fair Value, beginning of period | $ / shares	$ 67.09
Granted, Number of Shares	65,000
Granted, Weighted Average Grant Date Fair Value | $ / shares	$ 74.48
Vested, Number of Shares	(57,000)	[1]
Vested, Weighted Average Grant Date Fair Value | $ / shares	$ 48.48
Forfeited, Number of Shares	(38,000)
Forfeited, Weighted Average Grant Date Fair Value | $ / shares	$ 48.48
Nonvested stock, Number of Shares, end of period	169,000
Nonvested stock, Weighted Average Grant Date Fair Value, end of period | $ / shares	$ 74.10
Restricted Stock Units and Awards [Abstract]
Targeted goal of performance based awards and units	100.00%
Performance Restricted Stock Units [Member] | Minimum [Member]
Restricted Stock Units and Awards [Abstract]
Percentage of performance-based awards earned by recipient	0.00%
Performance Restricted Stock Units [Member] | Maximum [Member]
Restricted Stock Units and Awards [Abstract]
Percentage of performance-based awards earned by recipient	200.00%
[1]	Service-based restricted stock vested during each fiscal year. Performance-based awards and units included at 100% of target goal; under the terms of the awards, the recipient may earn between 0% and 200% of the award.

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	3 Months Ended
	Apr. 02, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
Foreign tax payment related to South Korea customs audit	$ 1,600
Line of Credit Facility, Maximum Borrowing Capacity	850,000
Debt Issuance Costs, Net	2,137
Total fees due to Barclays	10,500
Fees paid to Barclays	1,000
Underwriting fees due to Barclays	17,000
Upfront fees due to Barclays	7,500
Potential termination fees due to Rofin-Sinar	65,000
Potential termination fees due to Barclays	$ 2,400

Stock Repurchase (Details)

Stock Repurchase (Details) - USD ($)	Jul. 25, 2014	Jan. 31, 2015	Oct. 03, 2015	Apr. 04, 2015	Dec. 27, 2014	Aug. 25, 2015	Jan. 21, 2015
Stock Repurchase [Line Items]
Stock Repurchase Program, Authorized Amount	$ 25,000,000
Stock Repurchased and Retired During Period, Shares				133,673	300,441
Stock repurchase, price paid per share	$ 57.55	$ 57.66
Total cost of stock repurchased, net	$ 17,300,000	$ 7,700,000
January 2015 repurchase program [Member]
Stock Repurchase [Line Items]
Stock Repurchase Program, Authorized Amount							$ 25,000,000
Stock Repurchased and Retired During Period, Shares			430,675
Stock repurchase, price paid per share			$ 58.05
Total cost of stock repurchased, net			$ 25,000,000
August 2015 repurchase program [Member]
Stock Repurchase [Line Items]
Stock Repurchase Program, Authorized Amount						$ 25,000,000
Stock Repurchased and Retired During Period, Shares			437,534
Stock repurchase, price paid per share			$ 57.14
Total cost of stock repurchased, net			$ 25,000,000

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 02, 2016	Apr. 04, 2015	Apr. 02, 2016	Apr. 04, 2015
Earnings Per Share, Basic and Diluted [Abstract]
Weighted average shares outstanding—basic	24,137,000	24,709,000	24,066,000	24,823,000
Dilutive effect of employee awards	225,000	182,000	233,000	219,000
Weighted average shares outstanding—diluted	24,362,000	24,891,000	24,299,000	25,042,000
Net income	$ 17,781	$ 18,413	$ 38,067	$ 35,843
Net income per basic share	$ 0.74	$ 0.75	$ 1.58	$ 1.44
Net income per diluted share	$ 0.73	$ 0.74	$ 1.57	$ 1.43
Earnings Per Share, Diluted, Other Disclosures [Abstract]
Dilutive securities excluded from calculation of dilutive shares	7,078	1,333	9,451	41,559

Other Income (Expense) (Details

Other Income (Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 02, 2016	Apr. 04, 2015	Apr. 02, 2016	Apr. 04, 2015
Component of Other Income (Expense), Nonoperating [Line Items]
Other - net	$ (2,013)	$ 1,843	$ (2,460)	$ 1,073
Foreign Exchange Contract [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Foreign exchange gain (loss)	(198)	1,080	(1,520)	(81)
Gain (Loss) On Deferred Compensation Investments, Net [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Gain on deferred compensation investments, net	(1,877)	671	(1,002)	1,055
Other Income [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other Income	$ 62	$ 92	$ 62	$ 99

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 02, 2016	Apr. 04, 2015	Apr. 02, 2016	Apr. 04, 2015	Jan. 02, 2016
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Estimated effective income tax rate	26.60%	23.70%	25.80%	24.90%
U.S. Federal statutory rate		35.00%	35.00%
Tax Credit Carryforward, Amount					$ 1.2
Anticipated capital contribution for the Korea exemption			$ 4

Segment Information (Details)

Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 02, 2016	Apr. 04, 2015	Apr. 02, 2016	Apr. 04, 2015
Segment Reporting Information [Line Items]
Net sales	$ 199,882	$ 203,721	$ 390,157	$ 404,336
Income (Loss) from Continuing Operations Attributable to Parent	26,004	22,132	53,287	46,441
Nonoperating Income (Expense)	(1,780)	1,990	(2,002)	1,305
Income before income taxes	24,224	24,122	51,285	47,746
Provision for income taxes	6,443	5,709	13,218	11,903
Net income	17,781	18,413	38,067	35,843
Other Operating Income (Expense), Net	(1,780)	1,990	(2,002)	1,305
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	24,224	24,122	51,285	47,746
Commercial Lasers and Components
Segment Reporting Information [Line Items]
Net sales	56,529	63,705	110,853	119,229
Operating Income (Loss)	1,584	2,279	3,399	2,982
Specialty Laser Systems
Segment Reporting Information [Line Items]
Net sales	143,353	140,016	279,304	285,107
Operating Income (Loss)	37,635	32,078	73,430	66,632
Corporate and other
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ (13,215)	$ (12,225)	$ (23,542)	$ (23,173)

Segment Information (Major Cust

Segment Information (Major Customers) (Details) - Customer Concentration Risk [Member] - customers	3 Months Ended		6 Months Ended
	Apr. 02, 2016	Apr. 04, 2015	Apr. 02, 2016	Apr. 04, 2015	Oct. 03, 2015
Sales [Member]
Concentration Risk [Line Items]
Number of Customers for Concentration of Risk	1	1	2	1
Accounts Receivable [Member]
Concentration Risk [Line Items]
Number of Customers, Concentration Risk, Accounts Receivable	2		2		1
Customer 1 [Member] | Sales [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	17.30%	17.40%	17.50%	18.00%
Customer 1 [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Number of Customers, Concentration Risk, Percentage	15.30%		15.30%		21.40%
Customer 2 [Member] | Sales [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage			10.20%
Customer 2 [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Number of Customers, Concentration Risk, Percentage	19.30%		19.30%