nLIGHT (LASR) 10-K 26 Feb 21 2020 FY Annual report Financial data

Cover

Cover - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 22, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-38462
Entity Registrant Name	NLIGHT, INC.
Entity Incorporation, Date of Incorporation	DE
Entity Tax Identification Number	91-2066376
Entity Address, Address Line One	5408 NE 88th Street, Building E
Entity Address, City or Town	Vancouver
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98665
City Area Code	360
Local Phone Number	566-4460
Title of 12(b) Security	Common Stock, par value$0.0001 per share
Trading Symbol	LASR
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Smaller Reporting Company	false
Emerging Growth	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 845.5
Entity Common Stock, Shares Outstanding		40,134,273
Documents Incorporated by Reference	Portions of the registrant's definitive Proxy Statement for the 2021 Annual Meeting of Stockholders are incorporated herein by reference in Part III of this Annual Report on Form 10-K to the extent stated herein. Such Proxy Statement will be filed with the Securities and Exchange Commission within 120 days of the registrant's fiscal year ended December 31, 2020.
Entity Central Index Key	0001124796
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 102,282	$ 117,252
Accounts receivable, net of allowances of $367 and $269	31,820	27,126
Inventory	54,706	46,131
Prepaid expenses and other current assets	11,767	8,084
Total current assets	200,575	198,593
Restricted cash	291	41
Lease right-of-use assets	12,302
Property, plant and equipment, net of accumulated depreciation of $66,262 and $58,633	44,480	27,747
Intangible assets, net of accumulated amortization of $6,280 and $3,150	8,345	10,006
Goodwill	12,484	9,872
Other assets, net	5,167	3,707
Total assets	283,644	249,966
Current liabilities:
Accounts payable	21,057	12,700
Accrued liabilities	15,321	11,605
Deferred revenues	2,528	679
Current portion of lease liabilities	2,273
Current portion of long-term debt	184	51
Total current liabilities	41,363	25,035
Non-current income taxes payable	7,556	6,429
Long-term lease liabilities	10,375
Long-term debt	215	0
Other long-term liabilities	4,221	1,894
Total liabilities	63,730	33,358
Stockholders' equity:
Common stock - $0.0001 par value; 190,000 shares authorized, 39,793 shares issued and outstanding at December 31, 2020, and 38,084 shares issued and outstanding at December 31, 2019	15	15
Additional paid-in capital	358,544	336,732
Accumulated other comprehensive loss	(259)	(2,685)
Accumulated deficit	(138,386)	(117,454)
Total stockholders’ equity	219,914	216,608
Total liabilities and stockholders’ equity	$ 283,644	$ 249,966

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Accounts receivable, allowances	$ 367	$ 269
Property and equipment, accumulated depreciation	66,262	58,633
Intangible assets, accumulated amortization	$ 6,280	$ 3,150
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	190,000	190,000
Common stock, shares issued (in shares)	39,793	38,084
Common stock, shares outstanding (in shares)	39,793	38,084

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Total revenue	$ 222,789	$ 176,619	$ 191,359
Total cost of revenue	163,425	124,280	124,398
Gross profit	59,364	52,339	66,961
Operating expenses:
Research and development	41,164	28,137	21,054
Sales, general, and administrative	39,248	34,111	28,844
Total operating expenses	80,412	62,248	49,898
Income (loss) from operations	(21,048)	(9,909)	17,063
Other income (expense):
Interest income, net	78	2,609	728
Other income (expense), net	378	535	(253)
Income (loss) before income taxes	(20,592)	(6,765)	17,538
Income tax expense	340	6,119	3,600
Net income (loss)	(20,932)	(12,884)	13,938
Less: Income allocated to participating securities	0	0	(4,415)
Net income (loss) attributable to common stockholders	$ (20,932)	$ (12,884)	$ 9,523
Net loss per share, basic (in dollars per share)	$ (0.55)	$ (0.35)	$ 0.38
Net loss per share, diluted (in dollars per share)	$ (0.55)	$ (0.35)	$ 0.32
Shares used in per share calculations:
Basic (in shares)	38,367	37,119	24,862
Diluted (in shares)	38,367	37,119	29,959
Products
Total revenue	$ 184,841	$ 174,059	$ 191,359
Total cost of revenue	128,255	122,013	124,398
Development
Total revenue	37,948	2,560	0
Total cost of revenue	$ 35,170	$ 2,267	$ 0

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (20,932)	$ (12,884)	$ 13,938
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	2,426	(528)	(1,438)
Comprehensive income (loss)	$ (18,506)	$ (13,412)	$ 12,500

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	IPO	Follow-On Offering	Common stock	Common stockIPO	Common stockFollow-On Offering	Additional paid-in capital	Additional paid-in capitalIPO	Additional paid-in capitalFollow-On Offering	Accumulated other comprehensive income (loss)	Accumulated deficit	Convertible preferred stock	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, AdjustmentAdditional paid-in capital	Cumulative Effect, Period of Adoption, AdjustmentAccumulated deficit
Preferred stock, shares outstanding, beginning balance (in shares) at Dec. 31, 2017												24,642
Preferred stock, value, outstanding at Dec. 31, 2017												$ 12
Beginning balance (in shares) at Dec. 31, 2017				2,979
Beginning balance at Dec. 31, 2017	$ 61,283			$ 2			$ 180,657			$ (719)	$ (118,669)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	13,938										13,938
Shares of common stock issued upon conversion (in shares)				24,642								(24,642)
Conversion of convertible preferred stock to common stock	0			$ 12								$ (12)
Issuance of common stock (in shares)					6,900	1,520
Issuance of common stock		$ 100,948	$ 37,885		$ 1			$ 100,947	$ 37,885
Class of warrantor right shares converted (in shares)				160
Issuance of common stock pursuant to exercise of stock options (in shares)				387
Issuance of common stock pursuant to exercise of stock options	362						362
Issuance and conversion of restricted stock awards and units (in shares)				117
Stock-based compensation	4,805						4,805
Cumulative translation adjustment, net of tax	(1,438)									(1,438)
Preferred stock, shares outstanding, ending balance (in shares) at Dec. 31, 2018												0
Preferred stock, value, outstanding at Dec. 31, 2018												$ 0
Ending balance (in shares) at Dec. 31, 2018				36,705
Ending balance at Dec. 31, 2018	$ 217,783			$ 15			324,656			(2,157)	(104,731)		$ 0	$ (161)	$ 161
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201807Member
Net income (loss)	$ (12,884)										(12,884)
Issuance of common stock pursuant to exercise of stock options (in shares)				868
Issuance of common stock pursuant to exercise of stock options	1,560						1,560
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax (in shares)				428
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax	(524)						(524)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)				83
Issuance of common stock under the Employee Stock Purchase Plan	1,471						1,471
Stock-based compensation	9,730						9,730
Cumulative translation adjustment, net of tax	$ (528)									(528)
Preferred stock, shares outstanding, ending balance (in shares) at Dec. 31, 2019												0
Preferred stock, value, outstanding at Dec. 31, 2019												$ 0
Ending balance (in shares) at Dec. 31, 2019	38,084			38,084
Ending balance at Dec. 31, 2019	$ 216,608			$ 15			336,732			(2,685)	(117,454)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (20,932)										(20,932)
Issuance of common stock (in shares)	3,000
Issuance of common stock pursuant to exercise of stock options (in shares)	862			862
Issuance of common stock pursuant to exercise of stock options	$ 1,375						1,375
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax (in shares)				769
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax	$ (6,420)						(6,420)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)	78			78
Issuance of common stock under the Employee Stock Purchase Plan	$ 1,393						1,393
Stock-based compensation	25,464						25,464
Cumulative translation adjustment, net of tax	$ 2,426									2,426
Preferred stock, shares outstanding, ending balance (in shares) at Dec. 31, 2020												0
Preferred stock, value, outstanding at Dec. 31, 2020												$ 0
Ending balance (in shares) at Dec. 31, 2020	39,793			39,793
Ending balance at Dec. 31, 2020	$ 219,914			$ 15			$ 358,544			$ (259)	$ (138,386)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ (20,932)	$ (12,884)	$ 13,938
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation	7,710	6,583	5,867
Amortization	5,975	2,981	2,421
Reduction in carrying amount of right-of-use assets	2,916
Provision for losses on accounts receivable	88	83	22
Stock-based compensation	25,464	9,730	4,805
Deferred income taxes	(11)	3,041	(1,307)
(Gain) loss on disposal of assets	0	(483)	12
Loss on debt extinguishment	0	0	12
Changes in operating assets and liabilities:
Accounts receivable, net	(4,009)	(395)	(13,734)
Inventory	(6,937)	(10,670)	(6,145)
Prepaid expenses and other current assets	(3,442)	(111)	(2,483)
Other assets	(3,463)	(2,669)	(2,221)
Accounts payable	7,306	844	172
Accrued and other long-term liabilities	2,269	92	(310)
Deferred revenues	1,800	(178)	(215)
Lease liabilities	(2,820)
Non-current income taxes payable	1,127	(205)	2,542
Net cash provided by (used in) operating activities	13,041	(4,241)	3,376
Cash flows from investing activities:
Acquisition of business, net of cash acquired	(190)	(17,400)	0
Purchases of property, plant and equipment	(23,416)	(12,403)	(10,582)
Capitalization of patents	(933)	(1,229)	(1,132)
Proceeds from sale of assets	0	628	35
Net cash used in investing activities	(24,539)	(30,404)	(11,679)
Cash flows from financing activities:
Proceeds from term loan and debt financing	15,000	0	16,053
Principal payments on term loan, debt and financing leases	(15,115)	(55)	(33,417)
Proceeds from public offerings, net of offering costs	0	0	138,303
Proceeds from employee stock plan purchases	1,393	1,471	0
Proceeds from stock option exercises	1,375	1,560	362
Tax payments related to stock award issuances	(6,420)	(524)	0
Net cash provided by (used in) financing activities	(3,767)	2,452	121,301
Effect of exchange rate changes on cash	545	(33)	(166)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(14,720)	(32,226)	112,832
Cash, cash equivalents, and restricted cash, beginning of period	117,293	149,519	36,687
Cash, cash equivalents, and restricted cash, end of period	102,573	117,293	149,519
Supplemental disclosures:
Cash received (paid) for interest	311	2,802	(941)
Cash paid for income taxes	647	2,335	3,665
Accrued purchases of property, equipment and patents	788	828	577
Accrued acquisition consideration	1,441	$ 0	$ 0
Supplemental disclosure of noncash investing and financing activities:
Right-of-use assets obtained in exchange for lease liabilities	$ 15,127

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements include the accounts of nLIGHT, Inc. and its wholly owned subsidiaries (collectively, nLIGHT or the Company). The wholly owned subsidiaries are Arbor Photonics, LLC, nLIGHT Cayman Ltd., nLIGHT Laser Technology (Shanghai) Co. Ltd, nLIGHT Oy (Finland), nLIGHT Korea Inc., Nutronics, Inc., and OPI Photonics S.r.l. All intercompany balances have been eliminated. Use of Estimates The preparation of consolidated financial statements in conformity with accounting principles generally accepted (GAAP) in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates, including those related to inventory valuation, allowances for doubtful accounts, warranty, sales return reserves and the recoverability of long-lived assets. Management of the Company bases its estimates on historical experience and on various other assumptions. Actual results could differ from those estimates. Revenue Recognition See Note 3 for a detailed description of the Company's revenue recognition policies. Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less when acquired to be cash equivalents. Cash equivalents included $75.7 million and $96.7 million of highly liquid investments at December 31, 2020 and 2019, respectively. Cash equivalents are carried at cost, which approximates market. Inventory See Note 7 for a detailed description of the Company's inventory accounting policies. Property, Plant and Equipment Property, plant and equipment are stated at cost. Improvements and replacements are capitalized. Repair and maintenance costs are expensed as incurred. Depreciation is computed using the straight‑line method over the estimated useful life of each asset, generally 2 to 12 years for property and equipment, and 30 years for buildings. Land is not depreciated. Goodwill Goodwill is recorded when the purchase price of an acquisition exceeds the fair market value of the net assets acquired. Goodwill is not amortized and is tested for impairment at least annually and more frequently if material changes in events or circumstances arise. The Company performs an annual impairment review of goodwill in the fourth quarter of each year using either a qualitative assessment or a quantitative goodwill impairment test. If the qualitative assessment is selected and determines that the fair value of each reporting unit more likely than not exceeds its carrying value, no further assessment is necessary. If a quantitative test is determined necessary and an impairment is indicated, the impairment loss is recorded to the extent that the reporting unit’s carrying amount exceeds the reporting unit’s fair value. An impairment loss cannot exceed the total amount of goodwill allocated to the reporting unit. Based on qualitative assessments performed in fiscal years 2020, 2019 and 2018, the fair values of the Laser Products and Advanced Development reporting units exceeded their carrying values, and no impairment charges were recorded. See Note 10 for additional information. Intangible Assets Definite-lived intangible assets consist of acquisition-related development programs, developed technology, and intellectual property. The intangible assets are being amortized using the straight-line method over periods of 2 to 5 years, which reflect the pattern in which economic benefits of the assets are expected to be realized. See Note 10 for additional information. Impairment of Long‑Lived Assets Long‑lived assets, such as property, plant and equipment, and intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the fair value of the asset. There was no impairment of long‑lived assets recorded for the years ended December 31, 2020, 2019 and 2018. Leases See Note 15 for a detailed description of the Company's lease accounting policies. Research and Development Costs Research and development is defined as activities aimed at developing or significantly improving a product or a process or technique whether the product or process is intended for sale or use. A process also may be used internally as a part of a manufacturing activity. Research and development costs are expensed as incurred. Income Taxes The Company accounts for income taxes using the asset and liability approach under which deferred income taxes are provided based upon enacted tax laws and rates applicable to the periods in which taxes become payable. The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely to be realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. Translation of Foreign Currencies The Company’s international subsidiaries use their local currency as their functional currency. The financial statements of the international subsidiaries are translated to their U.S. dollar equivalents at end‑of‑period currency exchange rates for assets and liabilities and at average currency exchange rates for revenues and expenses. Translation adjustments are recorded as a component of accumulated other comprehensive loss within stockholders’ equity. Realized and unrealized foreign currency gains or losses, net are recorded in other expense within the consolidated statements of operations. Realized and unrealized foreign currency gains and losses were as follows for the periods presented (in thousands): Year Ended December 31, 2020 2019 2018 Realized foreign currency loss $ 98 $ 575 $ 734 Unrealized foreign currency (gain) loss (171) (381) 124 New Accounting Pronouncements ASU 2016-02, ASU 2018-10, ASU 2018-11 and ASU 2019-01 The Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-02, Leases (Topic 842) , in February 2016. ASU 2016-02 requires the recognition of right-of-use (ROU) assets and lease liabilities on the balance sheet for virtually all leases, other than leases that meet the definition of short-term. ASU 2016-02 was amended in July 2018, March 2019 and February 2020. The Company adopted ASU 2016-02, as amended, on January 1, 2020 using the modified transition approach, resulting in the recognition of operating lease ROU assets and lease liabilities of $7.6 million and $7.9 million, respectively. Refer to Note 15 for additional information. ASU 2016-13, ASU 2018-19, ASU 2019-04, ASU 2019-05 and ASU 2020-03 The FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , in June 2016. ASU 2016-13 replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. For assets measured at amortized cost, the new standard requires that the income statement reflects the measurement of credit losses for newly recognized financial assets, as well as the expected increases or decreases of expected credit losses that have taken place during the period. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. ASU 2016-13 was amended in November 2018, April 2019 and March 2020. ASU 2016-13, as amended, is effective for the Company's interim and annual reporting periods beginning after December 15, 2020. An entity will apply the new standard, as amended, using a modified-retrospective approach and record a cumulative effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The Company does not expect its adoption of ASU 2016-13, as amended to have a material impact on the Company's financial position, results of operations and cash flows. ASU 2019-12 The FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes , in December 2019. ASU 2019-12 removes certain exceptions to the general principles in Topic 740. The amendments also improve consistent application of and simplifies GAAP for other areas of Topic 740 by clarifying and amending existing guidance. ASU 2019-12 is effective for the Company's interim and annual reporting periods beginning after December 15, 2020. An entity will apply the new standard on the retrospective, modified retrospective or prospective basis, depending on the amendment. Early adoption is permitted, including adoption in any interim period for which financial statements have not yet been issued. The Company does not expect its adoption of ASU 2019-12 to have a material impact on the Company's financial position, results of operations and cash flows. ASU 2020-04 The FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting , in March 2020. ASU 2020-04 provides optional practical expedients and exceptions for applying U.S. GAAP to contracts and other transactions affected by reference rate reform if certain criteria are met. ASU 2020-04 applies only to contracts and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. ASU 2020-04 is effective for all entities for the period March 12, 2020 through December 31, 2022, and will not apply to contract modifications made after December 31, 2022. If elected, the optional expedients for contract modifications must be applied consistently for all eligible contracts or eligible transactions. Adoption of the ASU as of its effective date had no material impact on the Company's financial position, results of operations and cash flows.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Acquisitions	Acquisitions OPI On July 30, 2020, the Company acquired the outstanding shares of OPI Photonics S.r.l. (OPI), an Italian limited liability company, for cash consideration of approximately $1.6 million. Approximately $0.2 million was paid at closing with the remaining $1.4 million to be paid over the next 24 months. Located in Turin, Italy, OPI develops high power multi-emitter laser diode sources and innovative devices for kilowatt fiber laser beam management, including beam collimation, coupling and switching. The acquisition price was allocated to $0.7 million of tangible and $1.2 million of identified intangible assets acquired and $1.0 million of liabilities assumed as of the acquisition date based upon their respective fair values. The excess of purchase price over the fair value amounts assigned to the assets acquired and liabilities assumed represents $0.8 million of goodwill resulting from the acquisition. The fair values assigned to assets acquired and liabilities assumed were based on management’s best estimates and assumptions as of the reporting date and are considered preliminary. Changes to amounts recorded as assets or liabilities may result in corresponding adjustments to goodwill. The intangible assets acquired, developed technology, have a weighted-average useful life of 5 years. The goodwill and operating results of OPI are allocated to the Company's Laser Products segment. Revenue and earnings since the date of acquisition are not material. Transaction costs of $0.1 million were expensed as incurred as a component of Sales, general, and administrative expenses. Pro forma financial information has not been provided for the purchase as it was not material to the Company’s overall financial position. Nutronics On November 14, 2019, the Company acquired Nutronics, Inc. (Nutronics), a private company, pursuant to the Stock Purchase Agreement between nLIGHT, Inc. and selling stockholders of Nutronics, Inc. and sellers as of that date. The total acquisition consideration consisted of $17.4 million in cash. Based in Longmont, Colorado, Nutronics is a leading developer of coherently combined lasers and beam control systems (BCS) for high-energy laser (HEL) systems serving the defense market. The acquisition price was allocated to the tangible and identified intangible assets acquired and liabilities assumed as of the closing date of the acquisition based upon their respective fair values. The fair values assigned to assets acquired and liabilities assumed were based on management’s best estimates and assumptions, including future tax elections, as of the reporting date and are considered final. During the year ended December 31, 2020, updated information primarily related to a 2020 tax election resulted in an increase to deferred taxes and other liabilities acquired of approximately $1.8 million and a corresponding adjustment to goodwill. The purchase price allocation is now final. The table below summarizes the assets acquired and liabilities assumed at the acquisition date for the year ended December 31, 2020 (in thousands): Amounts Cash $ 33 Accounts receivable 635 Contract assets 456 Inventory 255 Other current assets 201 Property, plant and equipment 1,019 Security deposits 46 Tangible assets acquired 2,645 Accounts payable (278) Other liabilities (574) Deferred revenue (141) Deferred taxes (1,667) Liabilities assumed (2,660) Total tangible assets acquired and liabilities assumed (15) Intangible assets 7,200 Goodwill 10,248 Net assets acquired $ 17,433 The intangible assets as of the November 14, 2019 acquisition date were as follows (in thousands): Amount Weighted-Average Useful Life (in years) Development programs $ 7,200 3.1 Pro forma financial information has not been provided for the purchase as it was not material to the Company’s overall financial position.

Revenue

Revenue	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue	Revenue We adopted ASU 2014-09, Revenue from Contracts with Customers (Topic 606) and related amendments, using the cumulative effect method with a date of initial application of January 1, 2019. As such, the comparative period information has not been adjusted and continues to be reported under ASC 605 “ Revenue Recognition. ” The impact of adoption was immaterial, and we expect the impact of the adoption of the new standard to be immaterial to the consolidated financial statements on an ongoing basis. A majority of our revenue continues to be recognized at a point in time when control transfers based on the terms of the underlying contract. Revenue from our cost plus fixed fee research and development contracts are recognized over time. We recognize revenue upon transferring control of products and services, and the amounts recognized reflect the consideration we expect to be entitled to receive in exchange for these products and services. We consider customer purchase orders, which in some cases are governed by master sales agreements, to be the contracts with a customer. As part of our consideration of the contract, we evaluate certain factors, including the customer's ability to pay (or credit risk). For each contract, we consider the promise to transfer products, each of which is distinct, as the identified performance obligations. We allocate the transaction price to each distinct product based on its relative standalone selling price. Master sales agreements or purchase orders from customers could include a single product or multiple products. Regardless, the contracted price with the customer is agreed to at the individual product level outlined in the customer contract or purchase order. We do not bundle prices; however, we do negotiate with customers on pricing for the same products based on a variety of factors (e.g., level of contractual volume). We have concluded that the prices negotiated with each individual customer are representative of the stand-alone selling price of the product. We often receive orders with multiple delivery dates that may extend across several reporting periods. We allocate the transaction price of the contract to each delivery based on the product standalone selling price and invoice for each scheduled delivery upon shipment or delivery and recognize revenues for such delivery at that point, assuming transfer of control has occurred. Rights of return generally are not included in customer contracts. Accordingly, product revenue is recognized upon shipment or delivery, as applicable, and transfer of control. Rights of return are evaluated as they occur. Revenues recognized at a point in time consist of sales of semiconductor lasers, fiber lasers and other related products. Revenues recognized over time generally consist of development arrangements that are structured based on our costs incurred. Because control transfers over time, revenue is recognized based on the extent of progress towards completion of the performance obligation. We generally use the cost-to-cost measure of progress for our contracts because it best depicts the transfer of control to the customer. Billing under these arrangements generally occurs within one month after the work is completed. The following tables represent a disaggregation of revenue from contracts with customers for the periods presented (in thousands): Sales by End Market Year Ended December 31, 2020 2019 2018 Industrial $ 84,478 $ 76,668 $ 82,763 Microfabrication 51,649 57,153 74,108 Aerospace and Defense 86,662 42,798 34,488 $ 222,789 $ 176,619 $ 191,359 Sales by Geography Year Ended December 31, 2020 2019 2018 North America $ 107,624 $ 67,511 $ 70,694 China 70,882 64,134 70,196 Rest of World 44,283 44,974 50,469 $ 222,789 $ 176,619 $ 191,359 Sales by Timing of Revenue Year Ended December 31, 2020 2019 2018 Point in time $ 185,215 $ 168,699 $ 185,989 Over time 37,574 7,920 5,370 $ 222,789 $ 176,619 $ 191,359 The Company's contract assets and liabilities are as follows (in thousands): Balance Sheet Classification As of December 31, 2020 2019 Contract assets Prepaid expenses and $ 5,680 $ 2,449 Contract liabilities Deferred revenue and Other long-term liabilities 2,985 881 During the years ended December 31, 2020 and 2019, the Company recognized revenue of $0.4 million and $1.2 million, respectively, that was included in the deferred revenue balances at the beginning of the periods as the performance obligations under the associated agreements were satisfied.

Concentrations of Credit and Ot

Concentrations of Credit and Other Risks	12 Months Ended
	Dec. 31, 2020
Risks and Uncertainties [Abstract]
Concentrations of Credit and Other Risks	Concentrations of Credit and Other Risks The following customers accounted for 10% or more of the Company's revenues for the periods presented: Year Ended December 31, 2020 2019 2018 Quick Laser Technology Co., Ltd. 12% 11% 13% Raytheon Technologies 12% 13% (1) U.S. Government 15% (1) (1) (1) Represents less than 10% of total revenues

Accounts Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Accounts Receivable	Accounts Receivable Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The allowance for doubtful accounts is the Company’s best estimate of the amount of probable credit losses in the Company’s existing accounts receivable. The Company determines the allowance based on historical write‑off experience and knowledge of any applicable circumstances. Activity related to the allowance for doubtful accounts was as follows for the periods presented (in thousands): 2020 2019 Allowance for doubtful accounts, beginning $ 269 $ 303 Provision for losses on accounts receivable 88 83 Recoveries and (write-offs) 10 (117) Allowance for doubtful accounts, ending $ 367 $ 269

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of certain of the Company’s financial instruments, including cash equivalents, accounts receivable, restricted cash, and accounts payable are shown at cost which approximates fair value due to the short-term nature of these instruments. The fair value of the Company’s term and revolving loans with Pacific Western Bank, also described in Note 14, approximates the carrying value due to the variable market rate used to calculate interest payments. The Company does not have any other significant financial assets or liabilities that are measured at fair value. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The standard describes a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value which are the following: • Level 1 Inputs: Observable inputs, such as quoted prices (unadjusted) in active markets for identical assets or liabilities at the measurement date. • Level 2 Inputs: Observable inputs, other than Level 1 prices, such as quoted prices in active markets for similar assets and liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3 Inputs: Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The Company’s financial instruments that are carried at fair value consist of Level 1 assets which include highly liquid investments and bank drafts classified as cash equivalents. The Company's fair value hierarchy for its financial instruments consists of cash equivalents as follows (in thousands): December 31, 2020 Level 1 Level 2 Level 3 Total Money market securities $ 74,084 $ — $ — $ 74,084 Commercial paper 1,584 — — 1,584 Total $ 75,668 $ — $ — $ 75,668 December 31, 2019 Level 1 Level 2 Level 3 Total Money market securities $ 94,260 $ — $ — $ 94,260 Commercial paper 2,401 — — 2,401 Total $ 96,661 $ — $ — $ 96,661

Inventory

Inventory	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory is stated at the lower of average cost (principally standard cost, which approximates actual cost on a first-in, first-out basis) and net realizable value. Inventory includes raw materials and components that may be specialized in nature and subject to obsolescence. On a quarterly basis, we review inventory quantities on hand in comparison to our past consumption, recent purchases, and other factors to determine what inventory quantities, if any, may not be sellable. Based on this analysis, we write down the affected inventory value for estimated excess and obsolescence charges. At the point of loss recognition, a new, lower-cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established cost basis. Inventory consisted of the following (in thousands): As of December 31, 2020 2019 Raw materials $ 21,410 $ 16,643 Work in process and semi-finished goods 21,320 17,723 Finished goods 11,976 11,765 $ 54,706 $ 46,131

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets The components of prepaid expenses and other current assets are as follows (in thousands): As of December 31, 2020 2019 Contract assets $ 5,680 $ 2,449 Prepaid tax and duties 2,018 3,090 Prepaid expenses 1,417 1,688 Value-added tax receivable, net 308 468 Vendor prepayments 2,274 164 Other 70 225 $ 11,767 $ 8,084

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and EquipmentProperty, plant and equipment consist of the following (in thousands): As of December 31, Useful life (years) 2020 2019 Automobile 3 $ 34 $ — Computer hardware and software 3-5 4,840 4,764 Manufacturing and lab equipment 2-7 69,849 59,395 Office equipment and furniture 5-7 1,605 1,462 Leasehold and building improvements 2-12 21,934 20,759 Buildings 30 9,081 — Land N/A 3,399 — 110,742 86,380 Accumulated depreciation (66,262) (58,633) $ 44,480 $ 27,747 On March 31, 2020, the Company purchased a commercial property in Camas, Washington that consists of approximately 21 acres of land and two buildings with approximately 165,000 square feet of office space, clean rooms and manufacturing space. The property was purchased "as is," and the Company intends to use the property as its new headquarters following the completion of certain renovations and modifications.

Intangible Assets and Goodwill

Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets and Goodwill	Intangible Assets and Goodwill Intangibles The details of amortizing intangible assets are as follows (in thousands, except for estimated useful lives): Estimated useful life As of December 31, 2020 2019 Patents 3 - 5 $ 6,199 $ 5,956 Development programs 2 - 4 7,200 7,200 Developed technology 5 1,226 — 14,625 13,156 Accumulated amortization (6,280) (3,150) $ 8,345 $ 10,006 Estimated amortization expense for future years is as follows (in thousands): 2021 $ 3,889 2022 2,330 2023 1,648 2024 342 2025 136 $ 8,345 Goodwill The carrying amount of goodwill by segment was as follows (in thousands): Laser Products Advanced Development Totals Balance, December 31, 2019 $ 1,388 $ 8,484 $ 9,872 Business acquisition 814 — 814 Purchase accounting adjustment — 1,764 1,764 Currency exchange rate adjustment 34 — 34 Balance, December 31, 2020 $ 2,236 $ 10,248 $ 12,484

Other Assets

Other Assets	12 Months Ended
	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	Other Assets Other assets consisted of the following (in thousands): As of December 31, 2020 2019 Demonstration assets, net $ 2,598 $ 1,824 Deferred tax assets, net 69 72 Other 2,500 1,811 $ 5,167 $ 3,707 Demonstration (demo) assets are equipment that is used for demonstration and other purposes with existing and prospective customers. Demo assets are recorded at cost and amortized over an estimated useful life of approximately two years. Amortization expense was as follows for the periods presented (in thousands): Year Ended December 31, 2020 2019 2018 Amortization expense $ 2,166 $ 1,873 $ 1,821

Accrued Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities consist of the following (in thousands): As of December 31, 2020 2019 Accrued payroll and benefits $ 10,770 $ 8,208 Product warranty, current 2,122 1,683 Income tax payable 401 155 Other accrued expenses 2,028 1,559 $ 15,321 $ 11,605

Product Warranties

Product Warranties	12 Months Ended
	Dec. 31, 2020
Guarantees and Product Warranties [Abstract]
Product Warranties	Product Warranties The Company provides warranties on certain products and records a liability for the estimated future costs associated with warranty claims at the time revenue is recognized. The warranty liability is based on historical experience, any specifically identified failures, and its estimate of future costs. Product warranty liability activity was as follows for the periods presented (in thousands): Year Ended December 31, 2020 2019 Product warranty liability, beginning $ 2,984 $ 4,555 Warranty charges incurred, net (3,425) (2,382) Provision for warranty charges, net of adjustments 5,052 811 Acquired warranty 100 — Product warranty liability, ending $ 4,711 $ 2,984 Less: current portion of product warranty liability (2,122) (1,683) Non-current portion of product warranty liability $ 2,589 $ 1,301

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases See Note 15. Credit Facilities The Company has a $40.0 million revolving line of credit (LOC) with Pacific Western Bank which is secured by its assets and expires in September 2021. Interest on the LOC is based primarily on the London Interbank Offered Rate (LIBOR), or an alternative rate such as the Prime rate, plus or minus, respectively, a margin based on certain liquidity levels. The loan agreement contains restrictive and financial covenants and bears an unused credit fee of 0.20% on an annualized basis. As of December 31, 2020 and 2019, no amounts were outstanding under the LOC, and the Company was in compliance with all covenants under the loan agreement. Contingencies Liabilities for loss contingencies are recorded when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. The Company becomes involved in various legal proceedings and claims incidental to normal business activities. As of December 31, 2020, the Company believes these matters will not have a material adverse effect on the consolidated financial statements.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Leases Adoption of ASC 842 The Company adopted ASU 2016-02, Leases (Topic 842) and related amendments, using the modified transition approach with an effective date of January 1, 2020. The modified transition approach permits a company to use its effective date as the date of initial application to apply the standard to its leases, and, therefore, not restate comparative prior period financial information. Consequently, prior period financial information is not updated, and the disclosures required under the new standard will not be provided for dates and periods prior to January 1, 2020. The adoption of the lease standard did not have any effect on our previously reported consolidated financial statements and did not result in a cumulative catch-up adjustment to opening equity. Transition Practical Expedients and Elections The standard provides several optional practical expedients in transition. The Company elected the ‘package of practical expedients,’ which permits it to not reassess, under the new standard, the Company's prior conclusions about lease identification, lease classification and initial direct costs. The Company did not elect the use-of-hindsight or the practical expedient pertaining to land easements; the latter not being applicable to it. The new standard also provides practical expedients for an entity’s ongoing accounting. The Company elected the short-term lease recognition exemption; for those leases that qualify, the Company will not recognize a right-of-use asset or lease liability, and this includes not recognizing right-of-use assets or lease liabilities for existing short-term leases of those assets in transition. The Company also elected the practical expedient to not separate lease and non-lease components for all its leases. Lease Accounting The Company leases real estate space under non-cancelable operating lease agreements for commercial and industrial space, as well as its corporate headquarters located in Vancouver, Washington. Facilities-related operating leases have remaining terms of 0.1 to 14.4 years, and some leases include options to extend up to 15 years. Other leases for automobiles, manufacturing and office and computer equipment have remaining lease terms of 0.2 to 5.4 years. These leases are primarily operating leases; financing leases are not material. The Company did not include any renewal options in its lease terms for calculating the lease liabilities as the Company is not reasonably certain it will exercise the options at this time. The weighted-average remaining lease term for the lease obligations was 9.0 years at December 31, 2020, and the weighted-average discount rate was 3.5%. The Company had deposits on leased facilities of $0.5 million and $0.6 million as of December 31, 2020 and 2019, respectively, related primarily to its facilities in China and the U.S. The components of lease expense related to operating leases were as follows (in thousands): Year Ended December 31, 2020 2019 2018 Lease expense: Operating lease expense $ 3,052 $ 3,199 $ 3,070 Short-term lease expense 242 — — Variable and other lease expense 503 — — $ 3,797 $ 3,199 $ 3,070 Future minimum payments under our non-cancelable lease obligations were as follows as of December 31, 2020 (in thousands): 2021 $ 2,646 2022 2,064 2023 1,604 2024 1,557 2025 1,118 Thereafter 5,911 Total minimum lease payments 14,900 Less: interest (2,252) Present value of net minimum lease payments 12,648 Less: current portion of lease liabilities (2,273) Total long-term lease liabilities $ 10,375

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income (loss) before income taxes was as follows (in thousands): Year Ended December 31, 2020 2019 2018 Domestic $ (28,963) $ (14,298) $ 10,901 Foreign 8,371 7,533 6,637 Income (loss) before income taxes $ (20,592) $ (6,765) $ 17,538 Income tax provision was as follows (in thousands): Year Ended December 31, 2020 2019 2018 Current tax expense (benefit): State $ 21 $ (1) $ 9 Foreign 2,209 3,130 5,032 Current tax expense 2,230 3,129 5,041 Deferred tax expense (benefit): Federal (1,603) 4 — State (60) — — Foreign (227) 2,986 (1,441) Deferred tax expense (benefit) (1,890) 2,990 (1,441) Income tax expense $ 340 $ 6,119 $ 3,600 The income tax provision differs from the amount computed by applying the statutory federal income tax rate of 21% to the loss before income taxes as a result of the following differences (in thousands): Year Ended December 31, 2020 2019 2018 Tax computed at federal statutory rate $ (4,324) $ (1,347) $ 3,683 State tax, net of federal tax benefit (209) (133) 27 Permanent items 477 (1,493) 545 Stock compensation (2,669) (1,241) (497) Foreign dividends and unremitted earnings 726 (352) 159 Foreign rate differential 501 (308) (347) Rate change due to tax reform 1,563 125 2,819 Federal credits (639) (611) (619) Tax contingencies, net of reversals (677) 1,888 2,140 Return to provision (2,242) (379) (323) Other (112) 28 (717) Valuation allowance 7,945 9,942 (3,270) Income tax expense $ 340 $ 6,119 $ 3,600 The income tax expense recorded primarily relates to operations in China and Finland, which have income tax rates of 25% and 20%, respectively. The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are as follows (in thousands): Year Ended December 31, 2020 2019 2018 Deferred tax assets: Net operating loss carryforwards $ 28,718 $ 23,114 $ 16,407 Research and alternative minimum tax credits 5,583 5,022 4,501 Accrued expenses and other 5,648 3,671 2,806 Lease liabilities 2,547 — — Inventory 5,181 3,456 4,248 Property and equipment — 887 1,334 Total gross deferred tax assets 47,677 36,150 29,296 Less: valuation allowance (43,647) (35,545) (25,603) Total deferred tax assets 4,030 605 3,693 Deferred tax liabilities: Property and equipment (3) — — Intangible assets (1,490) (537) (579) Right-of-use assets (2,468) — — Total deferred tax liabilities (3,961) (537) (579) Net deferred tax assets $ 69 $ 68 $ 3,114 Net deferred tax assets of $0.1 million, $0.1 million, and $3.1 million as of December 31, 2020, 2019 and 2018, respectively, are included in other assets within the consolidated balance sheets. In evaluating its valuation allowance, the Company considers all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies, and recent financial performance. Due to uncertainty with respect to ultimate realizability of deferred tax assets, the Company has provided a valuation allowance against the U.S. and China deferred tax assets. The net change in the total valuation allowance for the years ended December 31, 2020, 2019 and 2018 were increases of $8.1 million and $9.9 million and a decrease of $3.3 million, respectively. At December 31, 2020, the Company has U.S., China and state net operating loss (NOL) carryforwards of $119.1 million, $11.8 million and $16.5 million, respectively. These carryforwards will expire from 2023 to 2040 if not used by the Company to reduce income taxes payable in future periods. The Company has U.S. research and development credit carryforwards of $6.7 million. These carryforwards will begin to expire between 2021 and 2040 if not used by the Company to reduce income taxes payable in future periods. Utilization of NOL carryforwards, credit carryforwards and certain deductions have been subject to annual limitations due to ownership change limitations provided by the Internal Revenue Code of 1986, as amended, (collectively, the IRC) and similar state provisions. Under Sections 382 and 383 of the IRC, substantial changes in the Company's ownership have required the Company to limit the amount of net operating loss and research and development credit carryforwards that were previously available to offset future taxable income. The Company performed a Section 382 analysis in 2018, and has had three "change in ownership" events that limit the utilization of NOL carryforwards. The "change in ownership" events occurred twice in August of 2000 and in January of 2001, and resulted in NOL carryforward limitations of $17 thousand, $52 thousand, and $459 thousand, respectively. Additional limitations on the use of these tax attributes could occur in the event of possible disputes arising in examination from various taxing authorities. The following table presents a reconciliation of the changes in the unrecognized tax benefit (in thousands): Balance at December 31, 2017 $ 2,517 Additions based on tax positions related to the current year 3,398 Additions for tax positions of prior years 92 Reductions for tax positions of prior years (49) Reductions as a result of a lapse of applicable statute of limitations (5) Other (66) Balance at December 31, 2018 $ 5,887 Additions based on tax positions related to the current year 2,925 Additions for tax positions of prior years 2 Reductions as a result of a lapse of applicable statute of limitations (22) Other (52) Balance at December 31, 2019 $ 8,740 Additions based on tax positions related to the current year 132 Additions for tax positions of prior years 4 Reductions for tax positions of prior years (1,285) Reductions as a result of a lapse of applicable statute of limitations (53) Other 321 Balance at December 31, 2020 $ 7,859 At December 31, 2020, the Company has $7.9 million of unrecognized tax benefits (excluding interest and penalties). Of this amount, $3.7 million is recorded in non-current income taxes payable and $4.2 million is recorded as an offset to non-current deferred tax assets on the accompanying consolidated balance sheet. The $4.2 million of unrecognized tax benefits in non-current deferred tax assets is entirely offset by a full valuation allowance in both the U.S. and China. Of the Company's unrecognized tax benefits, $3.7 million, if recognized, would impact the effective tax rate. At December 31, 2019, the Company had recorded $3.5 million of unrecognized tax benefits in non-current income taxes payable and $5.3 million of unrecognized tax benefits recognized as an offset to noncurrent deferred tax assets on the accompanying consolidated balance sheet. The Company does not expect a significant decrease to the total amount of unrecognized tax benefits within the next twelve months. The Company recognizes interest and penalties related to unrecognized tax benefits as a component of income tax expense. The Company has recognized penalties and interest during the years ended December 31, 2020, 2019 and 2018, of $0.5 million, $0.3 million, and $0.4 million, respectively. At December 31, 2020 and 2019, interest and penalties associated with unrecognized tax benefits were $2.1 million and $1.6 million, respectively. At December 31, 2020, the Company's tax years 2017 through 2020, 2016 through 2020, and 2010 through 2020, remain open for examination in the federal, state and foreign jurisdictions, respectively. However, to the extent allowed by law, the taxing authorities may have the right to examine prior periods where net operating losses and credits were generated and carried

Stockholders' Equity and Stock-

Stockholders' Equity and Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Stockholders' Equity and Stock-Based Compensation	Stockholders' Equity and Stock-Based Compensation Preferred Stock The Company has authorized 5.0 million shares of preferred stock, par value $0.0001, none of which is issued and outstanding. Common Stock Each share of common stock has the right to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the Board of Directors, subject to the prior rights of holders of all classes of stock outstanding having priority rights as to dividends. No dividends have been declared or paid as of December 31, 2020. Common Stock Repurchase Plan On November 14, 2019, the Company's Board of Directors authorized the repurchase of up to $10.0 million of its outstanding shares of common stock. As of December 31, 2020, no repurchases had been executed under the program. Equity Incentive Plan As of December 31, 2020, there were approximately 3.0 million shares available for issuance under the Company's equity incentive plan. The Company has granted restricted stock awards and units during the years ended December 31, 2020 and 2019, and has not granted any stock options or stock appreciation rights during the same periods. Restricted Stock Awards and Units Restricted stock award (RSA) and restricted stock unit (RSU) activity under the Company's equity incentive plan was as follows (in thousands, except weighted-average grant date fair values): Number of Restricted Stock Awards Weighted-Average Grant Date Fair Value RSAs at December 31, 2019 459 $ 20.49 Awards granted 310 22.54 Awards vested (116) 21.41 RSAs at December 31, 2020 653 $ 21.30 Number of Restricted Stock Units Weighted-Average Grant Date Fair Value RSUs at December 31, 2019 2,407 $ 19.47 Awards granted 1,187 21.89 Awards vested (689) 19.17 Awards forfeited (105) 20.24 RSUs at December 31, 2020 2,800 $ 20.54 The total grant date fair value of RSAs and RSUs vested during the year ended December 31, 2020 was $2.5 million and $13.2 million, respectively. Awards outstanding as of December 31, 2020 include 0.7 million performance-based awards that will vest upon meeting certain performance criteria. Stock Options The following table summarizes the Company’s stock option activity during the year ended December 31, 2020 (in thousands, except weighted-average exercise prices): Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Outstanding, December 31, 2019 4,239 $1.54 6.1 $79,443 Options exercised (862) $1.60 Options canceled (19) $1.51 Outstanding, December 31, 2020 3,358 $1.53 5.3 $104,510 Options exercisable at December 31, 2020 2,752 $1.11 5.0 $86,784 Options vested as of December 31, 2020 and expected to vest after December 31, 2020 3,358 $1.53 5.3 $104,510 Total intrinsic value of options exercised for the years ended December 31, 2020 and 2019 was $17.0 million and $15.8 million, respectively. The Company received proceeds of $1.4 million and $1.6 million from the exercise of options for the years ended December 31, 2020 and 2019, respectively. Employee Stock Purchase Plan Information related to activity under the Company's Employee Stock Purchase Plan (ESPP) was as follows (in thousands, except weighted-average per share prices): Year Ended Shares issued 78 Weighted-average per share purchase price $ 17.85 Weighted-average per share discount from the fair value of our common stock on date of issuance $ 3.15 As of December 31, 2020, there were 2.2 million shares available for grant under the ESPP. Stock-Based Compensation Total stock-based compensation expense was included in our consolidated statements of operations as follows (in thousands): Year Ended December 31, 2020 2019 2018 Cost of revenues $ 1,621 $ 1,201 $ 456 Research and development 9,703 3,299 1,293 Sales, general and administrative 14,140 5,230 3,056 $ 25,464 $ 9,730 $ 4,805 Unrecognized Compensation Costs As of December 31, 2020, total unrecognized stock-based compensation related to unvested stock awards was $62.4 million, which will be recognized over the next five years as follows (in thousands): 2021 $ 26,688 2022 20,264 2023 12,542 2024 2,863 $ 62,357 Total unrecognized stock-based compensation includes approximately 0.6 million awards that do not have a measurement date and have been valued as of December 31, 2020.

401(k) Plan

401(k) Plan	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
401(k) Plan	401(k) Plan The Company has a 401(k) Profit Sharing Plan and Trust (the Plan). Participation in the Plan is voluntary and is available to all employees. The Company may make discretionary matching or qualified nonelective contributions to the Plan. The match is recorded within the cost of revenues and operating expenses in the consolidated statements of operations and were as follows for the periods presented (in thousands): Year Ended December 31, 2020 2019 2018 401(k) match $ 715 $ 668 $ 606

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segment Information	Segment Information The Company operates in two reportable segments consisting of the Laser Products segment and the Advanced Development segment. The following table summarizes the operating results by reportable segment for the periods presented (dollars in thousands): Year Ended December 31, 2020 Laser Products Advanced Development Corporate and Other Totals Revenue $ 184,841 $ 37,948 $ — $ 222,789 Gross profit $ 58,207 $ 2,778 $ (1,621) $ 59,364 Gross margin 31.5 % 7.3 % NM 26.6 % Year Ended December 31, 2019 Laser Products Advanced Development Corporate and Other Totals Revenue $ 174,059 $ 2,560 $ — $ 176,619 Gross profit $ 53,247 $ 293 $ (1,201) $ 52,339 Gross margin 30.6 % 11.4 % NM 29.6 % Corporate and Other is unallocated expenses related to stock-based compensation. The geographic locations of the Company’s long‑lived assets, net, based on location of the assets, are as follows (in thousands): As of December 31, 2020 2019 North America $ 67,625 $ 39,257 China 11,425 9,797 Rest of World 4,019 2,319 $ 83,069 $ 51,373

Net Loss per Share

Net Loss per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss per Share The following table sets forth the calculation of basic and diluted net loss per share for the periods presented (in thousands, except per share amounts): Year Ended December 31, 2020 2019 2018 Numerator: Net income (loss) $ (20,932) $ (12,884) $ 13,938 Participating securities Income allocated to participating securities — — (4,415) Net income (loss) attributable to common stockholders (20,932) (12,884) 9,523 Denominator: Weighted-average shares, basic 38,367 37,119 24,862 Dilutive effect of restricted stock units and awards — — 11 Dilutive effect of common stock options — — 5,086 Weighted-average shares, diluted 38,367 37,119 29,959 Net income (loss) per share attributable to common stockholders Basic $ (0.55) $ (0.35) $ 0.38 Diluted $ (0.55) $ (0.35) $ 0.32 The following potentially dilutive shares of restricted stock awards and units, employee stock purchase plan, and stock options were not included in the calculation of diluted shares above as the effect would have been anti‑dilutive (in thousands): Year Ended December 31, 2020 2019 2018 Restricted stock units and awards 2,903 2,426 622 Employee stock purchase plan 34 — — Common stock options 3,358 4,239 — 6,295 6,665 622

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event On January 1, 2021, the Company entered into a lease amendment related to its Hillsboro, Oregon facilities. The agreement included lease modifications that extended the lease term on the Company's existing premises. The lease, as modified, includes a minimum lease term of 145 months. The lease modification resulted in increases to the Company's balance sheet of approximately $3.4 million each in right-of-use assets and lease liabilities as of the lease modification date.

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of PresentationThe accompanying consolidated financial statements include the accounts of nLIGHT, Inc. and its wholly owned subsidiaries (collectively, nLIGHT or the Company). The wholly owned subsidiaries are Arbor Photonics, LLC, nLIGHT Cayman Ltd., nLIGHT Laser Technology (Shanghai) Co. Ltd, nLIGHT Oy (Finland), nLIGHT Korea Inc., Nutronics, Inc., and OPI Photonics S.r.l. All intercompany balances have been eliminated.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with accounting principles generally accepted (GAAP) in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates, including those related to inventory valuation, allowances for doubtful accounts, warranty, sales return reserves and the recoverability of long-lived assets. Management of the Company bases its estimates on historical experience and on various other assumptions. Actual results could differ from those estimates.
Revenue Recognition	Revenue Recognition We adopted ASU 2014-09, Revenue from Contracts with Customers (Topic 606) and related amendments, using the cumulative effect method with a date of initial application of January 1, 2019. As such, the comparative period information has not been adjusted and continues to be reported under ASC 605 “ Revenue Recognition. ” The impact of adoption was immaterial, and we expect the impact of the adoption of the new standard to be immaterial to the consolidated financial statements on an ongoing basis. A majority of our revenue continues to be recognized at a point in time when control transfers based on the terms of the underlying contract. Revenue from our cost plus fixed fee research and development contracts are recognized over time. We recognize revenue upon transferring control of products and services, and the amounts recognized reflect the consideration we expect to be entitled to receive in exchange for these products and services. We consider customer purchase orders, which in some cases are governed by master sales agreements, to be the contracts with a customer. As part of our consideration of the contract, we evaluate certain factors, including the customer's ability to pay (or credit risk). For each contract, we consider the promise to transfer products, each of which is distinct, as the identified performance obligations. We allocate the transaction price to each distinct product based on its relative standalone selling price. Master sales agreements or purchase orders from customers could include a single product or multiple products. Regardless, the contracted price with the customer is agreed to at the individual product level outlined in the customer contract or purchase order. We do not bundle prices; however, we do negotiate with customers on pricing for the same products based on a variety of factors (e.g., level of contractual volume). We have concluded that the prices negotiated with each individual customer are representative of the stand-alone selling price of the product. We often receive orders with multiple delivery dates that may extend across several reporting periods. We allocate the transaction price of the contract to each delivery based on the product standalone selling price and invoice for each scheduled delivery upon shipment or delivery and recognize revenues for such delivery at that point, assuming transfer of control has
Cash and Cash Equivalents	Cash and Cash EquivalentsThe Company considers all highly liquid investments with a maturity of three months or less when acquired to be cash equivalents.Cash equivalents are carried at cost, which approximates market.
Inventory	InventoryInventory is stated at the lower of average cost (principally standard cost, which approximates actual cost on a first-in, first-out basis) and net realizable value. Inventory includes raw materials and components that may be specialized in nature and subject to obsolescence. On a quarterly basis, we review inventory quantities on hand in comparison to our past consumption, recent purchases, and other factors to determine what inventory quantities, if any, may not be sellable. Based on this analysis, we write down the affected inventory value for estimated excess and obsolescence charges. At the point of loss recognition, a new, lower-cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established cost basis.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are stated at cost. Improvements and replacements are capitalized. Repair and maintenance costs are expensed as incurred. Depreciation is computed using the straight‑line method over the estimated useful life of each asset, generally 2 to 12 years for property and equipment, and 30 years for buildings. Land is not depreciated.
Goodwill	Goodwill Goodwill is recorded when the purchase price of an acquisition exceeds the fair market value of the net assets acquired. Goodwill is not amortized and is tested for impairment at least annually and more frequently if material changes in events or circumstances arise. The Company performs an annual impairment review of goodwill in the fourth quarter of each year using either a qualitative assessment or a quantitative goodwill impairment test. If the qualitative assessment is selected and determines that the fair value of each reporting unit more likely than not exceeds its carrying value, no further assessment is necessary. If a quantitative test is determined necessary and an impairment is indicated, the impairment loss is recorded to the extent that the reporting unit’s carrying amount exceeds the reporting unit’s fair value. An impairment loss cannot exceed the total amount of goodwill allocated to the reporting unit.
Intangible Assets	Intangible AssetsDefinite-lived intangible assets consist of acquisition-related development programs, developed technology, and intellectual property. The intangible assets are being amortized using the straight-line method over periods of 2 to 5 years, which reflect the pattern in which economic benefits of the assets are expected to be realized.
Impairment of Long-Lived Assets	Impairment of Long‑Lived Assets Long‑lived assets, such as property, plant and equipment, and intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the fair
Leases	Leases Adoption of ASC 842 The Company adopted ASU 2016-02, Leases (Topic 842) and related amendments, using the modified transition approach with an effective date of January 1, 2020. The modified transition approach permits a company to use its effective date as the date of initial application to apply the standard to its leases, and, therefore, not restate comparative prior period financial information. Consequently, prior period financial information is not updated, and the disclosures required under the new standard will not be provided for dates and periods prior to January 1, 2020. The adoption of the lease standard did not have any effect on our previously reported consolidated financial statements and did not result in a cumulative catch-up adjustment to opening equity. Transition Practical Expedients and Elections
Research and Development Costs	Research and Development Costs Research and development is defined as activities aimed at developing or significantly improving a product or a process or technique whether the product or process is intended for sale or use. A process also may be used internally as a part of a manufacturing activity. Research and development costs are expensed as incurred.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability approach under which deferred income taxes are provided based upon enacted tax laws and rates applicable to the periods in which taxes become payable. The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely to be realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.
Translation of Foreign Currencies	Translation of Foreign CurrenciesThe Company’s international subsidiaries use their local currency as their functional currency. The financial statements of the international subsidiaries are translated to their U.S. dollar equivalents at end‑of‑period currency exchange rates for assets and liabilities and at average currency exchange rates for revenues and expenses. Translation adjustments are recorded as a component of accumulated other comprehensive loss within stockholders’ equity. Realized and unrealized foreign currency gains or losses, net are recorded in other expense within the consolidated statements of operations.
New Accounting Pronouncements	New Accounting Pronouncements ASU 2016-02, ASU 2018-10, ASU 2018-11 and ASU 2019-01 The Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-02, Leases (Topic 842) , in February 2016. ASU 2016-02 requires the recognition of right-of-use (ROU) assets and lease liabilities on the balance sheet for virtually all leases, other than leases that meet the definition of short-term. ASU 2016-02 was amended in July 2018, March 2019 and February 2020. The Company adopted ASU 2016-02, as amended, on January 1, 2020 using the modified transition approach, resulting in the recognition of operating lease ROU assets and lease liabilities of $7.6 million and $7.9 million, respectively. Refer to Note 15 for additional information. ASU 2016-13, ASU 2018-19, ASU 2019-04, ASU 2019-05 and ASU 2020-03 The FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , in June 2016. ASU 2016-13 replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. For assets measured at amortized cost, the new standard requires that the income statement reflects the measurement of credit losses for newly recognized financial assets, as well as the expected increases or decreases of expected credit losses that have taken place during the period. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. ASU 2016-13 was amended in November 2018, April 2019 and March 2020. ASU 2016-13, as amended, is effective for the Company's interim and annual reporting periods beginning after December 15, 2020. An entity will apply the new standard, as amended, using a modified-retrospective approach and record a cumulative effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The Company does not expect its adoption of ASU 2016-13, as amended to have a material impact on the Company's financial position, results of operations and cash flows. ASU 2019-12 The FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes , in December 2019. ASU 2019-12 removes certain exceptions to the general principles in Topic 740. The amendments also improve consistent application of and simplifies GAAP for other areas of Topic 740 by clarifying and amending existing guidance. ASU 2019-12 is effective for the Company's interim and annual reporting periods beginning after December 15, 2020. An entity will apply the new standard on the retrospective, modified retrospective or prospective basis, depending on the amendment. Early adoption is permitted, including adoption in any interim period for which financial statements have not yet been issued. The Company does not expect its adoption of ASU 2019-12 to have a material impact on the Company's financial position, results of operations and cash flows. ASU 2020-04 The FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting , in March 2020. ASU 2020-04 provides optional practical expedients and exceptions for applying U.S. GAAP to contracts and other transactions affected by reference rate reform if certain criteria are met. ASU 2020-04 applies only to contracts and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. ASU 2020-04 is effective for all entities for the period March 12, 2020 through December 31, 2022, and will not apply to contract modifications made after December 31, 2022. If elected, the optional expedients for contract modifications must be applied consistently for all eligible contracts or eligible transactions. Adoption of the ASU as of its effective date had no material impact on the Company's financial position, results of operations and cash flows.
Product Warranties	The Company provides warranties on certain products and records a liability for the estimated future costs associated with warranty claims at the time revenue is recognized.  The warranty liability is based on historical experience, any specifically identified failures, and its estimate of future costs.

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Realized and Unrealized Foreign Currency Gains and Losses	Realized and unrealized foreign currency gains and losses were as follows for the periods presented (in thousands): Year Ended December 31, 2020 2019 2018 Realized foreign currency loss $ 98 $ 575 $ 734 Unrealized foreign currency (gain) loss (171) (381) 124

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Summary of Assets Acquired and Liabilities Assumed	The table below summarizes the assets acquired and liabilities assumed at the acquisition date for the year ended December 31, 2020 (in thousands): Amounts Cash $ 33 Accounts receivable 635 Contract assets 456 Inventory 255 Other current assets 201 Property, plant and equipment 1,019 Security deposits 46 Tangible assets acquired 2,645 Accounts payable (278) Other liabilities (574) Deferred revenue (141) Deferred taxes (1,667) Liabilities assumed (2,660) Total tangible assets acquired and liabilities assumed (15) Intangible assets 7,200 Goodwill 10,248 Net assets acquired $ 17,433
Schedule of Finite-Lived Intangible Assets Acquired	The intangible assets as of the November 14, 2019 acquisition date were as follows (in thousands): Amount Weighted-Average Useful Life (in years) Development programs $ 7,200 3.1

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Schedule of Sales by End Market	The following tables represent a disaggregation of revenue from contracts with customers for the periods presented (in thousands): Sales by End Market Year Ended December 31, 2020 2019 2018 Industrial $ 84,478 $ 76,668 $ 82,763 Microfabrication 51,649 57,153 74,108 Aerospace and Defense 86,662 42,798 34,488 $ 222,789 $ 176,619 $ 191,359
Schedule of Sales by Geography	Sales by Geography Year Ended December 31, 2020 2019 2018 North America $ 107,624 $ 67,511 $ 70,694 China 70,882 64,134 70,196 Rest of World 44,283 44,974 50,469 $ 222,789 $ 176,619 $ 191,359
Schedule of Sales by Timing of Revenue	Sales by Timing of Revenue Year Ended December 31, 2020 2019 2018 Point in time $ 185,215 $ 168,699 $ 185,989 Over time 37,574 7,920 5,370 $ 222,789 $ 176,619 $ 191,359
Schedule of Contract Assets and Liabilities	The Company's contract assets and liabilities are as follows (in thousands): Balance Sheet Classification As of December 31, 2020 2019 Contract assets Prepaid expenses and $ 5,680 $ 2,449 Contract liabilities Deferred revenue and Other long-term liabilities 2,985 881

Concentrations of Credit and _2

Concentrations of Credit and Other Risks (Tables)	12 Months Ended
	Dec. 31, 2020
Risks and Uncertainties [Abstract]
Schedule of Concentration of Credit	The following customers accounted for 10% or more of the Company's revenues for the periods presented: Year Ended December 31, 2020 2019 2018 Quick Laser Technology Co., Ltd. 12% 11% 13% Raytheon Technologies 12% 13% (1) U.S. Government 15% (1) (1)

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Schedule of Allowance for Doubtful Accounts	Activity related to the allowance for doubtful accounts was as follows for the periods presented (in thousands): 2020 2019 Allowance for doubtful accounts, beginning $ 269 $ 303 Provision for losses on accounts receivable 88 83 Recoveries and (write-offs) 10 (117) Allowance for doubtful accounts, ending $ 367 $ 269

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Fair Value Hierarchy for Its Cash Equivalents	The Company's fair value hierarchy for its financial instruments consists of cash equivalents as follows (in thousands): December 31, 2020 Level 1 Level 2 Level 3 Total Money market securities $ 74,084 $ — $ — $ 74,084 Commercial paper 1,584 — — 1,584 Total $ 75,668 $ — $ — $ 75,668 December 31, 2019 Level 1 Level 2 Level 3 Total Money market securities $ 94,260 $ — $ — $ 94,260 Commercial paper 2,401 — — 2,401 Total $ 96,661 $ — $ — $ 96,661

Inventory (Tables)

Inventory (Tables)	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Components of Inventory	Inventory consisted of the following (in thousands): As of December 31, 2020 2019 Raw materials $ 21,410 $ 16,643 Work in process and semi-finished goods 21,320 17,723 Finished goods 11,976 11,765 $ 54,706 $ 46,131

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Components of Prepaid Expenses and Other Current Assets	The components of prepaid expenses and other current assets are as follows (in thousands): As of December 31, 2020 2019 Contract assets $ 5,680 $ 2,449 Prepaid tax and duties 2,018 3,090 Prepaid expenses 1,417 1,688 Value-added tax receivable, net 308 468 Vendor prepayments 2,274 164 Other 70 225 $ 11,767 $ 8,084

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment	Property, plant and equipment consist of the following (in thousands): As of December 31, Useful life (years) 2020 2019 Automobile 3 $ 34 $ — Computer hardware and software 3-5 4,840 4,764 Manufacturing and lab equipment 2-7 69,849 59,395 Office equipment and furniture 5-7 1,605 1,462 Leasehold and building improvements 2-12 21,934 20,759 Buildings 30 9,081 — Land N/A 3,399 — 110,742 86,380 Accumulated depreciation (66,262) (58,633) $ 44,480 $ 27,747

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	The details of amortizing intangible assets are as follows (in thousands, except for estimated useful lives): Estimated useful life As of December 31, 2020 2019 Patents 3 - 5 $ 6,199 $ 5,956 Development programs 2 - 4 7,200 7,200 Developed technology 5 1,226 — 14,625 13,156 Accumulated amortization (6,280) (3,150) $ 8,345 $ 10,006
Schedule of Estimated Future Amortization Expense	Estimated amortization expense for future years is as follows (in thousands): 2021 $ 3,889 2022 2,330 2023 1,648 2024 342 2025 136 $ 8,345
Schedule of Goodwill	The carrying amount of goodwill by segment was as follows (in thousands): Laser Products Advanced Development Totals Balance, December 31, 2019 $ 1,388 $ 8,484 $ 9,872 Business acquisition 814 — 814 Purchase accounting adjustment — 1,764 1,764 Currency exchange rate adjustment 34 — 34 Balance, December 31, 2020 $ 2,236 $ 10,248 $ 12,484

Other Assets (Tables)

Other Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Other Assets	Other assets consisted of the following (in thousands): As of December 31, 2020 2019 Demonstration assets, net $ 2,598 $ 1,824 Deferred tax assets, net 69 72 Other 2,500 1,811 $ 5,167 $ 3,707 Year Ended December 31, 2020 2019 2018 Amortization expense $ 2,166 $ 1,873 $ 1,821

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consist of the following (in thousands): As of December 31, 2020 2019 Accrued payroll and benefits $ 10,770 $ 8,208 Product warranty, current 2,122 1,683 Income tax payable 401 155 Other accrued expenses 2,028 1,559 $ 15,321 $ 11,605

Product Warranties (Tables)

Product Warranties (Tables)	12 Months Ended
	Dec. 31, 2020
Guarantees and Product Warranties [Abstract]
Schedule of Reconciliation of the Changes in the Aggregate Product Warranty Liability	Product warranty liability activity was as follows for the periods presented (in thousands): Year Ended December 31, 2020 2019 Product warranty liability, beginning $ 2,984 $ 4,555 Warranty charges incurred, net (3,425) (2,382) Provision for warranty charges, net of adjustments 5,052 811 Acquired warranty 100 — Product warranty liability, ending $ 4,711 $ 2,984 Less: current portion of product warranty liability (2,122) (1,683) Non-current portion of product warranty liability $ 2,589 $ 1,301

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of Components of Lease Expense	The components of lease expense related to operating leases were as follows (in thousands): Year Ended December 31, 2020 2019 2018 Lease expense: Operating lease expense $ 3,052 $ 3,199 $ 3,070 Short-term lease expense 242 — — Variable and other lease expense 503 — — $ 3,797 $ 3,199 $ 3,070
Schedule of Future Minimum Payments Under Non-Cancelable Lease Obligations	Future minimum payments under our non-cancelable lease obligations were as follows as of December 31, 2020 (in thousands): 2021 $ 2,646 2022 2,064 2023 1,604 2024 1,557 2025 1,118 Thereafter 5,911 Total minimum lease payments 14,900 Less: interest (2,252) Present value of net minimum lease payments 12,648 Less: current portion of lease liabilities (2,273) Total long-term lease liabilities $ 10,375

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Net Income (Loss) Before Income Tax Expense	Income (loss) before income taxes was as follows (in thousands): Year Ended December 31, 2020 2019 2018 Domestic $ (28,963) $ (14,298) $ 10,901 Foreign 8,371 7,533 6,637 Income (loss) before income taxes $ (20,592) $ (6,765) $ 17,538
Income Tax Provision	Income tax provision was as follows (in thousands): Year Ended December 31, 2020 2019 2018 Current tax expense (benefit): State $ 21 $ (1) $ 9 Foreign 2,209 3,130 5,032 Current tax expense 2,230 3,129 5,041 Deferred tax expense (benefit): Federal (1,603) 4 — State (60) — — Foreign (227) 2,986 (1,441) Deferred tax expense (benefit) (1,890) 2,990 (1,441) Income tax expense $ 340 $ 6,119 $ 3,600
Schedule of Effective Income Tax Rate Reconciliation	The income tax provision differs from the amount computed by applying the statutory federal income tax rate of 21% to the loss before income taxes as a result of the following differences (in thousands): Year Ended December 31, 2020 2019 2018 Tax computed at federal statutory rate $ (4,324) $ (1,347) $ 3,683 State tax, net of federal tax benefit (209) (133) 27 Permanent items 477 (1,493) 545 Stock compensation (2,669) (1,241) (497) Foreign dividends and unremitted earnings 726 (352) 159 Foreign rate differential 501 (308) (347) Rate change due to tax reform 1,563 125 2,819 Federal credits (639) (611) (619) Tax contingencies, net of reversals (677) 1,888 2,140 Return to provision (2,242) (379) (323) Other (112) 28 (717) Valuation allowance 7,945 9,942 (3,270) Income tax expense $ 340 $ 6,119 $ 3,600
Schedule of Deferred Tax Assets And Deferred Tax Liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities are as follows (in thousands): Year Ended December 31, 2020 2019 2018 Deferred tax assets: Net operating loss carryforwards $ 28,718 $ 23,114 $ 16,407 Research and alternative minimum tax credits 5,583 5,022 4,501 Accrued expenses and other 5,648 3,671 2,806 Lease liabilities 2,547 — — Inventory 5,181 3,456 4,248 Property and equipment — 887 1,334 Total gross deferred tax assets 47,677 36,150 29,296 Less: valuation allowance (43,647) (35,545) (25,603) Total deferred tax assets 4,030 605 3,693 Deferred tax liabilities: Property and equipment (3) — — Intangible assets (1,490) (537) (579) Right-of-use assets (2,468) — — Total deferred tax liabilities (3,961) (537) (579) Net deferred tax assets $ 69 $ 68 $ 3,114
Reconciliation of Changes In Unrecognized Tax Benefit	The following table presents a reconciliation of the changes in the unrecognized tax benefit (in thousands): Balance at December 31, 2017 $ 2,517 Additions based on tax positions related to the current year 3,398 Additions for tax positions of prior years 92 Reductions for tax positions of prior years (49) Reductions as a result of a lapse of applicable statute of limitations (5) Other (66) Balance at December 31, 2018 $ 5,887 Additions based on tax positions related to the current year 2,925 Additions for tax positions of prior years 2 Reductions as a result of a lapse of applicable statute of limitations (22) Other (52) Balance at December 31, 2019 $ 8,740 Additions based on tax positions related to the current year 132 Additions for tax positions of prior years 4 Reductions for tax positions of prior years (1,285) Reductions as a result of a lapse of applicable statute of limitations (53) Other 321 Balance at December 31, 2020 $ 7,859

Stockholders' Equity and Stoc_2

Stockholders' Equity and Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Schedule of Restricted Stock Awards and Units	Restricted stock award (RSA) and restricted stock unit (RSU) activity under the Company's equity incentive plan was as follows (in thousands, except weighted-average grant date fair values): Number of Restricted Stock Awards Weighted-Average Grant Date Fair Value RSAs at December 31, 2019 459 $ 20.49 Awards granted 310 22.54 Awards vested (116) 21.41 RSAs at December 31, 2020 653 $ 21.30 Number of Restricted Stock Units Weighted-Average Grant Date Fair Value RSUs at December 31, 2019 2,407 $ 19.47 Awards granted 1,187 21.89 Awards vested (689) 19.17 Awards forfeited (105) 20.24 RSUs at December 31, 2020 2,800 $ 20.54
Schedule of Stock Option Activity	The following table summarizes the Company’s stock option activity during the year ended December 31, 2020 (in thousands, except weighted-average exercise prices): Number of Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Outstanding, December 31, 2019 4,239 $1.54 6.1 $79,443 Options exercised (862) $1.60 Options canceled (19) $1.51 Outstanding, December 31, 2020 3,358 $1.53 5.3 $104,510 Options exercisable at December 31, 2020 2,752 $1.11 5.0 $86,784 Options vested as of December 31, 2020 and expected to vest after December 31, 2020 3,358 $1.53 5.3 $104,510
Schedule of Employee Stock Purchase Plan	Information related to activity under the Company's Employee Stock Purchase Plan (ESPP) was as follows (in thousands, except weighted-average per share prices): Year Ended Shares issued 78 Weighted-average per share purchase price $ 17.85 Weighted-average per share discount from the fair value of our common stock on date of issuance $ 3.15
Schedule of Stock-based Compensation Expense	Total stock-based compensation expense was included in our consolidated statements of operations as follows (in thousands): Year Ended December 31, 2020 2019 2018 Cost of revenues $ 1,621 $ 1,201 $ 456 Research and development 9,703 3,299 1,293 Sales, general and administrative 14,140 5,230 3,056 $ 25,464 $ 9,730 $ 4,805
Schedule of Share-Based Payment Arrangement, Nonvested Award, Cost	As of December 31, 2020, total unrecognized stock-based compensation related to unvested stock awards was $62.4 million, which will be recognized over the next five years as follows (in thousands): 2021 $ 26,688 2022 20,264 2023 12,542 2024 2,863 $ 62,357

401(k) Plan (Tables)

401(k) Plan (Tables)	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Schedule of 401(k) Match	The match is recorded within the cost of revenues and operating expenses in the consolidated statements of operations and were as follows for the periods presented (in thousands): Year Ended December 31, 2020 2019 2018 401(k) match $ 715 $ 668 $ 606

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Summary of Operating Results by Reportable Segment	The following table summarizes the operating results by reportable segment for the periods presented (dollars in thousands): Year Ended December 31, 2020 Laser Products Advanced Development Corporate and Other Totals Revenue $ 184,841 $ 37,948 $ — $ 222,789 Gross profit $ 58,207 $ 2,778 $ (1,621) $ 59,364 Gross margin 31.5 % 7.3 % NM 26.6 % Year Ended December 31, 2019 Laser Products Advanced Development Corporate and Other Totals Revenue $ 174,059 $ 2,560 $ — $ 176,619 Gross profit $ 53,247 $ 293 $ (1,201) $ 52,339 Gross margin 30.6 % 11.4 % NM 29.6 %
Schedule of Revenue And Long-lived Assets By Geographical Areas	The geographic locations of the Company’s long‑lived assets, net, based on location of the assets, are as follows (in thousands): As of December 31, 2020 2019 North America $ 67,625 $ 39,257 China 11,425 9,797 Rest of World 4,019 2,319 $ 83,069 $ 51,373

Net Loss per Share (Tables)

Net Loss per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Income (Loss) per Share	The following table sets forth the calculation of basic and diluted net loss per share for the periods presented (in thousands, except per share amounts): Year Ended December 31, 2020 2019 2018 Numerator: Net income (loss) $ (20,932) $ (12,884) $ 13,938 Participating securities Income allocated to participating securities — — (4,415) Net income (loss) attributable to common stockholders (20,932) (12,884) 9,523 Denominator: Weighted-average shares, basic 38,367 37,119 24,862 Dilutive effect of restricted stock units and awards — — 11 Dilutive effect of common stock options — — 5,086 Weighted-average shares, diluted 38,367 37,119 29,959 Net income (loss) per share attributable to common stockholders Basic $ (0.55) $ (0.35) $ 0.38 Diluted $ (0.55) $ (0.35) $ 0.32
Schedule of Potentially Dilutive Shares Not Included in Calculation of Diluted Shares	The following potentially dilutive shares of restricted stock awards and units, employee stock purchase plan, and stock options were not included in the calculation of diluted shares above as the effect would have been anti‑dilutive (in thousands): Year Ended December 31, 2020 2019 2018 Restricted stock units and awards 2,903 2,426 622 Employee stock purchase plan 34 — — Common stock options 3,358 4,239 — 6,295 6,665 622

Basis of Presentation and Sig_4

Basis of Presentation and Significant Accounting Policies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and cash equivalents, fair value disclosure	$ 75,668,000	$ 96,661,000
Goodwill impairment	0	0	$ 0
Long-lived assets impairment	$ 0	$ 0	$ 0
Buildings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property and equipment useful life	30 years
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Average amortization period	2 years
Minimum | Property And Equipment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property and equipment useful life	2 years
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Average amortization period	5 years
Maximum | Property And Equipment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property and equipment useful life	12 years

Basis of Presentation and Sig_5

Basis of Presentation and Significant Accounting Policies - Realized and Unrealized Foreign Currency Gains and Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Realized foreign currency loss	$ 98	$ 575	$ 734
Unrealized foreign currency (gain) loss	$ (171)	$ (381)	$ 124

Basis of Presentation and Sig_6

Basis of Presentation and Significant Accounting Policies - New Accounting Pronouncements (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Jan. 01, 2020
Accounting Policies [Abstract]
Lease right-of-use assets	$ 12,302	$ 7,600
Present value of net minimum lease payments	$ 12,648	$ 7,900

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ in Thousands	Jul. 30, 2020	Nov. 14, 2019	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill			$ 12,484	$ 9,872
OPI Photonics
Business Acquisition [Line Items]
Acquisition consideration, cash	$ 1,600
Acquisition paid	200
Remaining amount	$ 1,400
Payment period	24 months
Tangible assets	$ 700
Intangible assets	1,200
Liabilities assumed	1,000
Goodwill	800
Transaction costs	$ 100
OPI Photonics | Developed technology
Business Acquisition [Line Items]
Weighted-Average Useful Life (in years)	5 years
Nutronics, Inc.
Business Acquisition [Line Items]
Acquisition consideration, cash		$ 17,400
Intangible assets			7,200
Liabilities assumed			2,660
Goodwill			10,248
Increase to deferred taxes and other liabilities acquired			$ 1,800

Acquisitions - Assets Acquired

Acquisitions - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Goodwill	$ 12,484	$ 9,872
Nutronics, Inc.
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Cash	33
Accounts receivable	635
Contract assets	456
Inventory	255
Other current assets	201
Property, plant and equipment	1,019
Security deposits	46
Tangible assets acquired	2,645
Accounts payable	(278)
Other liabilities	(574)
Deferred revenue	(141)
Deferred taxes	(1,667)
Liabilities assumed	(2,660)
Total tangible assets acquired and liabilities assumed	(15)
Intangible assets	7,200
Goodwill	10,248
Net assets acquired	$ 17,433

Acquisitions - Intangible Asset

Acquisitions - Intangible Assets (Details) - Nutronics, Inc. - USD ($) $ in Thousands	Nov. 14, 2019	Dec. 31, 2020
Business Acquisition [Line Items]
Amount		$ 7,200
Development programs
Business Acquisition [Line Items]
Amount	$ 7,200
Weighted-Average Useful Life (in years)	3 years 1 month 6 days

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenue	$ 222,789	$ 176,619	$ 191,359
Point in time
Disaggregation of Revenue [Line Items]
Total revenue	185,215	168,699	185,989
Over time
Disaggregation of Revenue [Line Items]
Total revenue	37,574	7,920	5,370
North America
Disaggregation of Revenue [Line Items]
Total revenue	107,624	67,511	70,694
China
Disaggregation of Revenue [Line Items]
Total revenue	70,882	64,134	70,196
Rest of World
Disaggregation of Revenue [Line Items]
Total revenue	44,283	44,974	50,469
Industrial
Disaggregation of Revenue [Line Items]
Total revenue	84,478	76,668	82,763
Microfabrication
Disaggregation of Revenue [Line Items]
Total revenue	51,649	57,153	74,108
Aerospace and Defense
Disaggregation of Revenue [Line Items]
Total revenue	$ 86,662	$ 42,798	$ 34,488

Revenue - Contract Assets and L

Revenue - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Contract assets	$ 5,680	$ 2,449
Contract liabilities	$ 2,985	$ 881

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue recognized, previously included in customer advances and deferred revenue	$ 0.4	$ 1.2

Concentrations of Credit and _3

Concentrations of Credit and Other Risks (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Sales Revenue | Quick Laser Technology Co., Ltd.
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%	11.00%	13.00%
Sales Revenue | Raytheon Technologies
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%	13.00%
Sales Revenue | U.S. Government
Concentration Risk [Line Items]
Concentration risk, percentage	15.00%
Accounts Receivable | Two Customers
Concentration Risk [Line Items]
Concentration risk, percentage	43.00%	48.00%

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for doubtful accounts, beginning	$ 269	$ 303
Provision for losses on accounts receivable	88	83	$ 22
Recoveries and (write-offs)	10	(117)
Allowance for doubtful accounts, ending	$ 367	$ 269	$ 303

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	$ 75,668	$ 96,661
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	75,668	96,661
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Money market securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	74,084	94,260
Money market securities | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	74,084	94,260
Money market securities | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Money market securities | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Commercial paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	1,584	2,401
Commercial paper | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	1,584	2,401
Commercial paper | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Commercial paper | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	$ 0	$ 0

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Raw materials	$ 21,410	$ 16,643
Work in process and semi-finished goods	21,320	17,723
Finished goods	11,976	11,765
Inventory	$ 54,706	$ 46,131

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Contract assets	$ 5,680	$ 2,449
Prepaid tax and duties	2,018	3,090
Prepaid expenses	1,417	1,688
Value-added tax receivable, net	308	468
Vendor prepayments	2,274	164
Other	70	225
Prepaid expenses and other current assets	$ 11,767	$ 8,084

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) ft² in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)	Mar. 31, 2020aft²building	Dec. 31, 2019USD ($)
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 110,742		$ 86,380
Accumulated depreciation	(66,262)		(58,633)
Property and equipment, net	$ 44,480		27,747
Automobile
Property, Plant and Equipment [Line Items]
Useful life (years)	3 years
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 34		0
Computer hardware and software
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 4,840		4,764
Computer hardware and software | Minimum
Property, Plant and Equipment [Line Items]
Useful life (years)	3 years
Computer hardware and software | Maximum
Property, Plant and Equipment [Line Items]
Useful life (years)	5 years
Manufacturing and lab equipment
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 69,849		59,395
Manufacturing and lab equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (years)	2 years
Manufacturing and lab equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (years)	7 years
Office equipment and furniture
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 1,605		1,462
Office equipment and furniture | Minimum
Property, Plant and Equipment [Line Items]
Useful life (years)	5 years
Office equipment and furniture | Maximum
Property, Plant and Equipment [Line Items]
Useful life (years)	7 years
Leasehold and building improvements
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 21,934		20,759
Leasehold and building improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful life (years)	2 years
Leasehold and building improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful life (years)	12 years
Buildings
Property, Plant and Equipment [Line Items]
Useful life (years)	30 years
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 9,081		0
Land
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 3,399		$ 0
Camas, Washington
Property, Plant and Equipment, Net [Abstract]
Area of land | a		21
Number of buildings | building		2
Area of office space | ft²		165

Intangible Assets and Goodwil_2

Intangible Assets and Goodwill - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 14,625	$ 13,156
Accumulated amortization	(6,280)	(3,150)
Net value	8,345	10,006
Patents
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	6,199	5,956
Development programs
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 7,200	7,200
Developed technology
Finite-Lived Intangible Assets [Line Items]
Average amortization period	5 years
Gross carrying amount	$ 1,226	$ 0
Minimum
Finite-Lived Intangible Assets [Line Items]
Average amortization period	2 years
Minimum | Patents
Finite-Lived Intangible Assets [Line Items]
Average amortization period	3 years
Minimum | Development programs
Finite-Lived Intangible Assets [Line Items]
Average amortization period	2 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Average amortization period	5 years
Maximum | Patents
Finite-Lived Intangible Assets [Line Items]
Average amortization period	5 years
Maximum | Development programs
Finite-Lived Intangible Assets [Line Items]
Average amortization period	4 years

Intangible Assets and Goodwil_3

Intangible Assets and Goodwill - Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
2021	$ 3,889
2022	2,330
2023	1,648
2024	342
2025	136
Net value	$ 8,345	$ 10,006

Intangible Assets and Goodwil_4

Intangible Assets and Goodwill - Goodwill (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Goodwill [Roll Forward]
Goodwill	$ 9,872
Business acquisition	814
Purchase accounting adjustment	1,764
Currency exchange rate adjustment	34
Goodwill	12,484
Laser Products
Goodwill [Roll Forward]
Goodwill	1,388
Business acquisition	814
Purchase accounting adjustment	0
Currency exchange rate adjustment	34
Goodwill	2,236
Advanced Development
Goodwill [Roll Forward]
Goodwill	8,484
Business acquisition	0
Purchase accounting adjustment	1,764
Currency exchange rate adjustment	0
Goodwill	$ 10,248

Other Assets (Details)

Other Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Assets, Noncurrent Disclosure [Abstract]
Demonstration assets, net	$ 2,598	$ 1,824
Deferred tax assets, net	69	72
Other	2,500	1,811
Other assets	$ 5,167	3,707
Useful life of demonstration assets	2 years
Amortization expense	$ 2,166	$ 1,873	$ 1,821

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued payroll and benefits	$ 10,770	$ 8,208
Product warranty, current	2,122	1,683
Income tax payable	401	155
Other accrued expenses	2,028	1,559
Total accrued liabilities	$ 15,321	$ 11,605

Product Warranties (Details)

Product Warranties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Movement in Standard Product Warranty Accrual [Roll Forward]
Product warranty liability, beginning	$ 2,984	$ 4,555
Warranty charges incurred, net	(3,425)	(2,382)
Provision for warranty charges, net of adjustments	5,052	811
Acquired warranty	100	0
Product warranty liability, ending	4,711	2,984
Less: current portion of product warranty liability	(2,122)	(1,683)
Non-current portion of product warranty liability	$ 2,589	$ 1,301

Commitments and Contingencies (

Commitments and Contingencies (Details) - Revolving Credit Facility - Line of Credit - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Line of Credit Facility [Line Items]
Revolving line of credit, borrowing capacity	$ 40,000,000
Unused credit fee (percent)	0.20%
Outstanding	$ 0	$ 0

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Weighted-average remaining lease term for operating leases	9 years
Weighted-average discount rate for operating leases	3.50%
Lease deposit	$ 0.5
Lease deposit		$ 0.6
Operating Leases, Excluding Automobiles
Lessee, Lease, Description [Line Items]
Renewal lease term	15 years
Operating Leases, Excluding Automobiles | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term	1 month 6 days
Operating Leases, Excluding Automobiles | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	14 years 4 months 24 days
Operating Leases, Automobiles | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term	2 months 12 days
Operating Leases, Automobiles | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	5 years 4 months 24 days

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease expense	$ 3,052
Short-term lease expense	242
Variable and other lease expense	503
Lease expense	$ 3,797
Rent expense, net		$ 3,199	$ 3,070

Leases - Future Minimum Payment

Leases - Future Minimum Payments Under Non-Cancelable Operating Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Jan. 01, 2020
Leases [Abstract]
2021	$ 2,646
2022	2,064
2023	1,604
2024	1,557
2025	1,118
Thereafter	5,911
Total minimum lease payments	14,900
Less: interest	(2,252)
Present value of net minimum lease payments	12,648	$ 7,900
Less: current portion of lease liabilities	(2,273)
Long-term lease liabilities	$ 10,375

Income Taxes - Net Income (Loss

Income Taxes - Net Income (Loss) Before Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Domestic	$ (28,963)	$ (14,298)	$ 10,901
Foreign	8,371	7,533	6,637
Income (loss) before income taxes	$ (20,592)	$ (6,765)	$ 17,538

Income Taxes - Income Tax Provi

Income Taxes - Income Tax Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current tax expense (benefit):
State	$ 21	$ (1)	$ 9
Foreign	2,209	3,130	5,032
Current tax expense	2,230	3,129	5,041
Deferred tax expense (benefit):
Federal	(1,603)	4	0
State	(60)	0	0
Foreign	(227)	2,986	(1,441)
Deferred tax expense (benefit)	(1,890)	2,990	(1,441)
Income tax expense	$ 340	$ 6,119	$ 3,600

Income Taxes - Tax Rate Reconci

Income Taxes - Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Tax computed at federal statutory rate	$ (4,324)	$ (1,347)	$ 3,683
State tax, net of federal tax benefit	(209)	(133)	27
Permanent items	477	(1,493)	545
Stock compensation	(2,669)	(1,241)	(497)
Foreign dividends and unremitted earnings	726	(352)	159
Foreign rate differential	501	(308)	(347)
Rate change due to tax reform	1,563	125	2,819
Federal credits	(639)	(611)	(619)
Tax contingencies, net of reversals	(677)	1,888	2,140
Return to provision	(2,242)	(379)	(323)
Other	(112)	28	(717)
Valuation allowance	7,945	9,942	(3,270)
Income tax expense	$ 340	$ 6,119	$ 3,600

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)event	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Income Tax [Line Items]
Statutory tax rate	21.00%
Net deferred tax assets	$ 69	$ 68	$ 3,114
Valuation allowance, deferred tax assets, increase (decrease)	$ 8,100	9,900	(3,300)
Number of change in ownership events | event	3
Unrecognized tax benefits	$ 7,859	8,740	5,887	$ 2,517
Unrecognized tax benefits, recognized penalties and interest	500	300	$ 400
Unrecognized tax benefits, income tax penalties and interest accrued	2,100	1,600
Non-current Income Taxes Payable
Income Tax [Line Items]
Unrecognized tax benefits	3,700	3,500
Non-current Deferred Tax Assets
Income Tax [Line Items]
Unrecognized tax benefits	4,200	$ 5,300
Research and Development Credit
Income Tax [Line Items]
Tax credit carryforward	6,700
U.S.
Income Tax [Line Items]
Operating loss carryforwards	119,100
Foreign Tax Authority
Income Tax [Line Items]
Operating loss carryforwards	11,800
State
Income Tax [Line Items]
Operating loss carryforwards	16,500
Change in ownership event one
Income Tax [Line Items]
Tax credit carryforward, limitation	17
Change in ownership event two
Income Tax [Line Items]
Tax credit carryforward, limitation	52
Change in ownership event three
Income Tax [Line Items]
Tax credit carryforward, limitation	$ 459
China | Foreign Tax Authority
Income Tax [Line Items]
Statutory tax rate	25.00%
Finland | Foreign Tax Authority
Income Tax [Line Items]
Statutory tax rate	20.00%

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 28,718	$ 23,114	$ 16,407
Research and alternative minimum tax credits	5,583	5,022	4,501
Accrued expenses and other	5,648	3,671	2,806
Lease liabilities	2,547
Inventory	5,181	3,456	4,248
Property and equipment	0	887	1,334
Total gross deferred tax assets	47,677	36,150	29,296
Less: valuation allowance	(43,647)	(35,545)	(25,603)
Total deferred tax assets	4,030	605	3,693
Deferred tax liabilities:
Property and equipment	(3)	0	0
Intangible assets	(1,490)	(537)	(579)
Right-of-use assets	(2,468)
Total deferred tax liabilities	(3,961)	(537)	(579)
Net deferred tax assets	$ 69	$ 68	$ 3,114

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 8,740	$ 5,887	$ 2,517
Additions based on tax positions related to the current year	132	2,925	3,398
Additions for tax positions of prior years	4	2	92
Reductions for tax positions of prior years	(1,285)		(49)
Reductions as a result of a lapse of applicable statute of limitations	(53)	(22)	(5)
Other	321	(52)	(66)
Ending balance	$ 7,859	$ 8,740	$ 5,887

Stockholders' Equity and Stoc_3

Stockholders' Equity and Stock-Based Compensation - Narrative (Details)	12 Months Ended
	Dec. 31, 2020USD ($)vote$ / sharesshares	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)	Nov. 14, 2019USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of votes each share of common stock has rights to (vote) | vote	1
Dividends | $	$ 0
Common stock repurchase plan, authorized | $				$ 10,000,000
Number of shares repurchased (in shares)	0
Issuance of common stock (in shares)	3,000,000
Intrinsic value of options exercised | $	$ 17,000,000	$ 15,800,000
Proceeds from the exercise of options | $	1,375,000	$ 1,560,000	$ 362,000
Unrecognized expense | $	62,400,000
Restricted Stock Awards (RSAs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, fair value | $	$ 2,500,000
Awards outstanding (in shares)	653,000	459,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, fair value | $	$ 13,200,000
Awards outstanding (in shares)	2,800,000	2,407,000
Performance Restricted Stock Awards and Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards outstanding (in shares)	700,000
Performance-based awards, performance goals not yet established (in shares)	600,000
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant (in shares)	2,200,000
Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, shares authorized (in shares)	5,000,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.0001
Preferred stock, shares issued (in shares)	0
Preferred stock, shares outstanding (in shares)	0

Stockholders' Equity and Stoc_4

Stockholders' Equity and Stock-Based Compensation - Summary of Restricted Stock Award and Restricted Stock Unit Activity (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Restricted Stock Awards
Number of restricted shares
Balance, beginning (in shares) | shares	459
Granted (in shares) | shares	310
Vested (in shares) | shares	(116)
Balance, ending (in shares) | shares	653
Weighted average exercise price
Balance, beginning (in dollars per share) | $ / shares	$ 20.49
Granted (in dollars per share) | $ / shares	22.54
Vested (in dollars per share) | $ / shares	21.41
Balance, ending (in dollars per share) | $ / shares	$ 21.30
Restricted Stock Units
Number of restricted shares
Balance, beginning (in shares) | shares	2,407
Granted (in shares) | shares	1,187
Vested (in shares) | shares	(689)
Forfeited & modified (in shares) | shares	(105)
Balance, ending (in shares) | shares	2,800
Weighted average exercise price
Balance, beginning (in dollars per share) | $ / shares	$ 19.47
Granted (in dollars per share) | $ / shares	21.89
Vested (in dollars per share) | $ / shares	19.17
Forfeited & modified (in dollars per share) | $ / shares	20.24
Balance, ending (in dollars per share) | $ / shares	$ 20.54

Stockholders' Equity and Stoc_5

Stockholders' Equity and Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Number of Options
Outstanding, beginning of period (in shares)	4,239
Options exercised (in shares)	(862)
Options canceled (in shares)	(19)
Outstanding, end of period (in shares)	3,358	4,239
Weighted-Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 1.54
Options exercised (in dollars per share)	1.60
Options canceled (in dollars per share)	1.51
Outstanding, end of period (in dollars per share)	$ 1.53	$ 1.54
Outstanding, Weighted average remaining contractual term (years)	5 years 3 months 18 days	6 years 1 month 6 days
Outstanding, Aggregate intrinsic value	$ 104,510	$ 79,443
Options exercisable at end of period
Options exercisable (in shares)	2,752
Weighted average exercise price (in dollars per share)	$ 1.11
Weighted average remaining contractual term (years)	5 years
Aggregate intrinsic value	$ 86,784
Options vested as of end of period and expected to vest after end of period
Options vested and expected to vest (in shares)	3,358
Weighted Average Remaining Contractual Term (Years)	5 years 3 months 18 days
Weighted average exercise price (in dollars per share)	$ 1.53
Aggregate Intrinsic Value	$ 104,510

Stockholders' Equity and Stoc_6

Stockholders' Equity and Stock-Based Compensation - Employee Stock Purchase Program (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Equity [Abstract]
Shares issued (in shares) | shares	78
Weighted average per share purchase price (in dollars per share)	$ 17.85
Weighted average per share discount from the fair value of our common stock on date of issuance (in dollars per share)	$ 3.15

Stockholders' Equity and Stoc_7

Stockholders' Equity and Stock-Based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 25,464	$ 9,730	$ 4,805
Cost of revenues
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	1,621	1,201	456
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	9,703	3,299	1,293
Sales, general and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 14,140	$ 5,230	$ 3,056

Stockholders' Equity and Stoc_8

Stockholders' Equity and Stock-Based Compensation - Unrecognized Compensation Costs (Details) $ in Thousands	Dec. 31, 2020USD ($)
Equity [Abstract]
2021	$ 26,688
2022	20,264
2023	12,542
2024	2,863
Total compensation cost	$ 62,357

401(k) Plan (Details)

401(k) Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
401(k) match	$ 715	$ 668	$ 606

Segment Information - Narrative

Segment Information - Narrative (Details)	12 Months Ended
	Dec. 31, 2020segment
Segment Reporting [Abstract]
Number of reportable segments	2

Segment Information - Operating

Segment Information - Operating Results (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenue	$ 222,789	$ 176,619	$ 191,359
Gross profit	$ 59,364	$ 52,339	$ 66,961
Gross margin	26.60%	29.60%
Operating Segments | Laser Products
Segment Reporting Information [Line Items]
Revenue	$ 184,841	$ 174,059
Gross profit	$ 58,207	$ 53,247
Gross margin	31.50%	30.60%
Operating Segments | Advanced Development
Segment Reporting Information [Line Items]
Revenue	$ 37,948	$ 2,560
Gross profit	$ 2,778	$ 293
Gross margin	7.30%	11.40%
Corporate and Other
Segment Reporting Information [Line Items]
Revenue	$ 0	$ 0
Gross profit	$ (1,621)	$ (1,201)

Segment Information - Geographi

Segment Information - Geographic Locations (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 83,069	$ 51,373
North America
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	67,625	39,257
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	11,425	9,797
Rest of World
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 4,019	$ 2,319

Net Loss per Share - Calculatio

Net Loss per Share - Calculation of Basic and Diluted Net Income (Loss) per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net loss	$ (20,932)	$ (12,884)	$ 13,938
Less: Income allocated to participating securities	0	0	(4,415)
Net income (loss) attributable to common stockholders	$ (20,932)	$ (12,884)	$ 9,523
Denominator:
Weighted-average shares, basic (in shares)	38,367	37,119	24,862
Weighted-average shares, diluted (in shares)	38,367	37,119	29,959
Net income (loss) per share attributable to common stockholders
Basic (in dollars per share)	$ (0.55)	$ (0.35)	$ 0.38
Diluted (in dollars per share)	$ (0.55)	$ (0.35)	$ 0.32
Restricted stock units and awards
Denominator:
Weighted-average shares, diluted (in shares)	0	0	11
Common stock options
Denominator:
Weighted-average shares, diluted (in shares)	0	0	5,086

Net Loss per Share - Antidiluti

Net Loss per Share - Antidilutive Securities Excluded from Dilutive Shares (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	6,295	6,665	622
Restricted stock units and awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	2,903	2,426	622
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	34	0	0
Common stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	3,358	4,239	0

Subsequent Event (Details)

Subsequent Event (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 31, 2020	Jan. 01, 2020
Subsequent Event [Line Items]
Right-of-use assets		$ 12,302	$ 7,600
Present value of net minimum lease payments		$ 12,648	$ 7,900
Hillsboro, Oregon Facilities | Subsequent Event
Subsequent Event [Line Items]
Minimum lease term	145 months
Right-of-use assets	$ 3,400
Present value of net minimum lease payments	$ 3,400