nLIGHT (LASR) 10-Q 6 Nov 20 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Nov. 02, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Smaller Reporting Company	false
Emerging Growth	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		39,365,991
Entity Central Index Key	0001124796
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 110,152	$ 117,252
Accounts receivable, net of allowances of $335 and $269	23,452	27,126
Inventory	53,432	46,131
Prepaid expenses and other current assets	12,996	8,084
Total current assets	200,032	198,593
Restricted cash	291	41
Lease right-of-use assets	11,428
Property, plant and equipment, net of accumulated depreciation of $63,513 and $58,633	42,365	27,747
Intangible assets, net of accumulated amortization of $5,972 and $3,150	9,088	10,006
Goodwill	12,503	9,872
Other assets, net	4,681	3,707
Total assets	280,388	249,966
Current liabilities:
Accounts payable	24,403	12,700
Accrued liabilities	14,663	11,605
Deferred revenues	2,124	679
Lease liabilities	2,347
Current portion of long-term debt	142	51
Total current liabilities	43,679	25,035
Non-current income taxes payable	7,219	6,429
Long-term lease liabilities	9,397
Long-term debt	205	0
Other long-term liabilities	3,796	1,894
Total liabilities	64,296	33,358
Stockholders' equity:
Common stock - $0.0001 par value; 190,000 shares authorized, 39,335 shares issued and outstanding at September 30, 2020, and 38,084 shares issued and outstanding at December 31, 2019	15	15
Additional paid-in capital	351,703	336,732
Accumulated other comprehensive loss	(1,757)	(2,685)
Accumulated deficit	(133,869)	(117,454)
Total stockholders’ equity	216,092	216,608
Total liabilities and stockholders’ equity	$ 280,388	$ 249,966

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Accounts receivable, allowances	$ 335	$ 269
Property and equipment, accumulated depreciation	63,513	58,633
Intangible assets, accumulated amortization	$ 5,972	$ 3,150
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	190,000,000	190,000,000
Common stock, shares issued (in shares)	39,335,000	38,084,000
Common stock, shares outstanding (in shares)	39,335,000	38,084,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Total revenue	$ 61,732	$ 43,814	$ 157,085	$ 133,723
Total cost of revenue	44,572	30,852	117,368	91,376
Gross profit	17,160	12,962	39,717	42,347
Operating expenses:
Research and development	11,126	6,402	29,136	19,318
Sales, general, and administrative	10,010	7,256	27,343	23,972
Total operating expenses	21,136	13,658	56,479	43,290
Loss from operations	(3,976)	(696)	(16,762)	(943)
Other income (expense):
Interest income (expense), net	(96)	665	122	2,155
Other income, net	477	90	63	3
Income (loss) before income taxes	(3,595)	59	(16,577)	1,215
Income tax expense (benefit)	(1,485)	837	(162)	3,383
Net loss	$ (2,110)	$ (778)	$ (16,415)	$ (2,168)
Net loss per share, basic (in dollars per share)	$ (0.05)	$ (0.02)	$ (0.43)	$ (0.06)
Net loss per share, diluted (in dollars per share)	$ (0.05)	$ (0.02)	$ (0.43)	$ (0.06)
Shares used in per share calculations:
Basic (in shares)	38,558	37,262	38,195	37,005
Diluted (in shares)	38,558	37,262	38,195	37,005
Products
Total revenue	$ 51,117	$ 43,814	$ 133,151	$ 133,723
Total cost of revenue	34,645	30,852	95,142	91,376
Development
Total revenue	10,615	0	23,934	0
Total cost of revenue	$ 9,927	$ 0	$ 22,226	$ 0

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (2,110)	$ (778)	$ (16,415)	$ (2,168)
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	1,091	(1,126)	928	(1,069)
Comprehensive loss	$ (1,019)	$ (1,904)	$ (15,487)	$ (3,237)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated deficit	Cumulative Effect, Period of Adoption, AdjustmentAdditional paid-in capital	Cumulative Effect, Period of Adoption, AdjustmentAccumulated deficit
Beginning balance (in shares) at Dec. 31, 2018		36,705
Beginning balance at Dec. 31, 2018	$ 217,783	$ 15	$ 324,656	$ (2,157)	$ (104,731)	$ (161)	$ 161
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(2,168)				(2,168)
Issuance of common stock pursuant to exercise of stock options (in shares)		595
Issuance of common stock pursuant to exercise of stock options	1,032		1,032
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax (in shares)		401
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax	(489)		(489)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)		43
Issuance of common stock under the Employee Stock Purchase Plan	762		762
Stock-based compensation	5,369		5,369
Cumulative translation adjustment	(1,069)			(1,069)
Ending balance (in shares) at Sep. 30, 2019		37,744
Ending balance at Sep. 30, 2019	221,220	$ 15	331,169	(3,226)	(106,738)
Beginning balance (in shares) at Jun. 30, 2019		37,665
Beginning balance at Jun. 30, 2019	221,937	$ 15	329,982	(2,100)	(105,960)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(778)				(778)
Issuance of common stock pursuant to exercise of stock options (in shares)		77
Issuance of common stock pursuant to exercise of stock options	117		117
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax (in shares)		2
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax	(9)		(9)
Stock-based compensation	1,079		1,079
Cumulative translation adjustment	(1,126)			(1,126)
Ending balance (in shares) at Sep. 30, 2019		37,744
Ending balance at Sep. 30, 2019	$ 221,220	$ 15	331,169	(3,226)	(106,738)
Beginning balance (in shares) at Dec. 31, 2019	38,084	38,084
Beginning balance at Dec. 31, 2019	$ 216,608	$ 15	336,732	(2,685)	(117,454)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (16,415)				(16,415)
Issuance of common stock pursuant to exercise of stock options (in shares)	633	633
Issuance of common stock pursuant to exercise of stock options	$ 1,117		1,117
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax (in shares)		579
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax	$ (3,314)		(3,314)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)	39	39
Issuance of common stock under the Employee Stock Purchase Plan	$ 685		685
Stock-based compensation	16,483		16,483
Cumulative translation adjustment	$ 928			928
Ending balance (in shares) at Sep. 30, 2020	39,335	39,335
Ending balance at Sep. 30, 2020	$ 216,092	$ 15	351,703	(1,757)	(133,869)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member
Beginning balance (in shares) at Jun. 30, 2020		38,850
Beginning balance at Jun. 30, 2020	$ 211,325	$ 15	345,917	(2,848)	(131,759)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(2,110)				(2,110)
Issuance of common stock pursuant to exercise of stock options (in shares)		115
Issuance of common stock pursuant to exercise of stock options	260		260
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax (in shares)		370
Issuance of common stock pursuant to vesting of restricted stock awards and units, net of stock withheld for tax	(1,157)		(1,157)
Stock-based compensation	6,683		6,683
Cumulative translation adjustment	$ 1,091			1,091
Ending balance (in shares) at Sep. 30, 2020	39,335	39,335
Ending balance at Sep. 30, 2020	$ 216,092	$ 15	$ 351,703	$ (1,757)	$ (133,869)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (16,415)	$ (2,168)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	5,614	4,859
Amortization	4,319	1,935
Reduction in carrying amount of right-of-use assets	2,162
Provision for losses on accounts receivable	84	58
Stock-based compensation	16,483	5,369
Gain on disposal of assets	0	(7)
Changes in operating assets and liabilities:
Accounts receivable, net	4,094	(2,836)
Inventory	(6,411)	(11,055)
Prepaid expenses and other current assets	(4,753)	2,590
Other assets	(2,418)	(2,670)
Accounts payable	10,565	3,290
Accrued and other long-term liabilities	1,494	(1,337)
Deferred revenues	1,405	(259)
Lease liabilities	(2,120)
Non-current income taxes payable	591	337
Net cash provided by (used in) operating activities	14,694	(1,894)
Cash flows from investing activities:
Acquisition of business, net of cash acquired	(168)	0
Purchases of property, plant and equipment	(19,395)	(8,943)
Capitalization of patents	(717)	(1,064)
Proceeds from sale of assets	0	19
Net cash used in investing activities	(20,280)	(9,988)
Cash flows from financing activities:
Proceeds from term loan	15,000	0
Principal payments on term loans and financing leases	(15,126)	(67)
Proceeds from employee stock plan purchases	685	762
Proceeds from stock option exercises	1,117	1,032
Tax payments related to stock award issuances	(3,314)	(489)
Net cash provided by (used in) financing activities	(1,638)	1,238
Effect of exchange rate changes on cash	373	29
Net decrease in cash, cash equivalents, and restricted cash	(6,851)	(10,615)
Cash, cash equivalents, and restricted cash, beginning of period	117,294	149,520
Cash, cash equivalents, and restricted cash, end of period	110,443	138,905
Supplemental disclosures:
Cash received for interest	312	2,265
Cash paid for income taxes	1,015	1,741
Accrued purchases of property, equipment and patents	1,294	1,275
Accrued acquisition consideration	1,390	$ 0
Supplemental disclosure of noncash investing and financing activities:
Right-of-use assets obtained in exchange for lease liabilities	$ 13,470

Basis of Presentation and New A

Basis of Presentation and New Accounting Pronouncements	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation and New Accounting Pronouncements	Basis of Presentation and New Accounting Pronouncements Basis of Presentation The accompanying consolidated financial statements of nLIGHT, Inc. and its wholly owned subsidiaries (Company) have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) and pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). The unaudited financial information reflects, in the opinion of management, all adjustments necessary for a fair presentation of financial position, results of operations, stockholders’ equity, and cash flows for the interim periods presented. The results reported for the interim period presented are not necessarily indicative of results that may be expected for the full year. These consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our 2019 Annual Report on Form 10-K. Reclassifications Certain immaterial reclassifications were made to the prior period financial statements to conform to the current period presentation. Critical Accounting Policies Other than the adoption of new lease accounting standards as described in Note 13, our critical accounting policies have not materially changed during the nine months ended September 30, 2020 from those disclosed in our Annual Report on Form 10-K for the year ended December 31, 2019. 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 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 annual reporting periods of emerging growth companies 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 is currently evaluating the impact on its consolidated financial statements and cannot reasonably estimate the impact on its financial statements at this time. ASU 2020-04 FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting,

Acquisition

Acquisition	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Acquisition	Acquisitions OPI On July 30, 2020, we acquired the outstanding shares of OPI Photonics S.r.l. (OPI), an Italian limited liability company, for cash consideration of approximately $1.6 million, including contingent consideration of up to $0.3 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 allocation of the purchase price for the OPI acquisition was as follows (in thousands): Valuation at July 30, 2020 Cash $ 58 Accounts receivable 73 Inventory 307 Other assets 186 Tangible assets acquired 624 Accounts payable (193) Deferred taxes (299) Debt (402) Other liabilities (164) Liabilities assumed (1,058) Total tangible assets and liabilities assumed (434) Intangible assets 1,179 Goodwill 869 Net assets acquired $ 1,614 The intangible assets as of the July 30, 2020 acquisition date were as follows (in thousands): Amount Weighted-Average Useful Life (in years) Developed technology $ 1,179 5.0 The acquisition price was allocated to the tangible and identified intangible assets acquired and 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 the amount 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 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 preliminary. During the nine months ended September 30, 2020, updated information primarily related to a 2020 tax election resulted in an increase to deferred taxes and other liabilities acquired of $1.8 million and a corresponding adjustment to goodwill. The table below summarizes the assets acquired and liabilities assumed (in thousands): Valuation as of Balances as of November 14, 2019 Adjustments September 30, 2020 Cash $ 33 $ — $ 33 Accounts receivable 635 — 635 Contract assets 456 — 456 Inventory 255 — 255 Other current assets 201 — 201 Property, plant and equipment 1,019 — 1,019 Security deposits 46 — 46 Tangible assets acquired 2,645 — 2,645 Accounts payable (278) — (278) Other liabilities (477) (100) (577) Deferred revenue (141) — (141) Deferred taxes — (1,667) (1,667) Liabilities assumed (896) (1,767) (2,663) Total tangible assets acquired and liabilities assumed 1,749 (1,767) (18) Intangible assets 7,200 7,200 Goodwill 8,484 1,767 10,251 Net assets acquired $ 17,433 $ — $ 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	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The following tables represent a disaggregation of revenue from contracts with customers for the periods presented (in thousands): Sales by End Market Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Industrial $ 21,880 $ 18,977 $ 60,500 $ 58,021 Microfabrication 14,052 13,280 38,771 45,907 Aerospace and Defense 25,800 11,557 57,814 29,795 $ 61,732 $ 43,814 $ 157,085 $ 133,723 Sales by Geography Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 North America $ 31,384 $ 16,382 $ 72,924 $ 50,294 China 19,186 17,397 52,723 49,251 Rest of World 11,162 10,035 31,438 34,178 $ 61,732 $ 43,814 $ 157,085 $ 133,723 Sales by Timing of Revenue Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Point in time $ 51,101 $ 42,458 $ 133,304 $ 129,951 Over time 10,631 1,356 23,781 3,772 $ 61,732 $ 43,814 $ 157,085 $ 133,723 The Company's contract assets and liabilities are as follows (in thousands): Balance Sheet Classification As of September 30, 2020 December 31, 2019 Contract assets Prepaid expenses and other current assets $ 5,178 $ 2,449 Contract liabilities Deferred revenue and Other long-term liabilities 2,524 881 During the three and nine months ended September 30, 2020, the Company recognized revenue of $0.8 million and $1.6 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	9 Months Ended
	Sep. 30, 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: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Quick Laser Technology Co., Ltd. 13% 12% 13% * U.S. Government 16% * 13% * Raytheon Technologies 12% 15% 13% 12% *Represents less than 10% of total revenues

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial InstrumentsThe 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 12, 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): September 30, 2020 Level 1 Level 2 Level 3 Total Money market securities $ 74,084 $ — $ — $ 74,084 Commercial paper 4,585 — — 4,585 Total $ 78,669 $ — $ — $ 78,669 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	9 Months Ended
	Sep. 30, 2020
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory is stated at the lower of average cost and net realizable value. Inventory consisted of the following (in thousands): As of September 30, 2020 December 31, 2019 Raw materials $ 19,740 $ 16,643 Work in process and semi-finished goods 22,693 17,723 Finished goods 10,999 11,765 $ 53,432 $ 46,131

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment consist of the following (in thousands): As of Useful life (years) September 30, 2020 December 31, 2019 Computer hardware and software 3-5 $ 4,625 $ 4,764 Manufacturing and lab equipment 2-7 65,893 59,395 Office equipment and furniture 5-7 1,410 1,462 Leasehold and building improvements 2-12 21,470 20,759 Buildings 30 9,081 — Land N/A 3,399 — 105,878 86,380 Accumulated depreciation (63,513) (58,633) $ 42,365 $ 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	9 Months Ended
	Sep. 30, 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 September 30, 2020 December 31, 2019 Patents 3 - 5 $ 6,689 $ 5,956 Development programs 2 - 4 7,200 7,200 Developed technology 5 1,171 — 15,060 13,156 Accumulated amortization (5,972) (3,150) $ 9,088 $ 10,006 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 869 — 869 Purchase accounting adjustment — 1,767 1,767 Currency exchange rate adjustment (5) — (5) Balance, September 30, 2020 $ 2,252 $ 10,251 $ 12,503 See Note 2 for details related to goodwill for the Nutronics and OPI acquisitions.

Other Assets

Other Assets	9 Months Ended
	Sep. 30, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	Other Assets Other assets consisted of the following (in thousands): As of September 30, 2020 December 31, 2019 Demonstration assets, net $ 1,965 $ 1,824 Deferred tax assets, net 72 72 Other 2,644 1,811 $ 4,681 $ 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): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Amortization expense $ 478 $ 454 $ 1,500 $ 1,355

Accrued Liabilities

Accrued Liabilities	9 Months Ended
	Sep. 30, 2020
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities consist of the following (in thousands): As of September 30, 2020 December 31, 2019 Accrued payroll and benefits $ 10,759 $ 8,208 Product warranty, current 1,982 1,683 Income tax payable — 155 Other accrued expenses 1,922 1,559 $ 14,663 $ 11,605

Product Warranties

Product Warranties	9 Months Ended
	Sep. 30, 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 for the nine months ended September 30, 2020 and 2019 was as follows (in thousands): Nine Months Ended September 30, 2020 2019 Product warranty liability, beginning $ 2,984 $ 4,555 Warranty charges incurred, net (2,259) (1,971) Provision for warranty charges, net of adjustments 3,425 456 Acquired warranty 100 — Product warranty liability, ending $ 4,250 $ 3,040 Less: current portion of product warranty liability (1,982) (1,725) Non-current portion of product warranty liability $ 2,268 $ 1,315

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases See Note 13. 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 September 30, 2020, no amounts were outstanding under the LOC, and the Company was in compliance with all covenants under the loan agreement. Contractual Commitments and Purchase Obligations The Company's purchase obligations and other contractual obligations have increased as of September 30, 2020 by approximately $11.7 million for operating leases as discussed in Note 13, and approximately $1.4 million for the earn-out and hold-back amounts related to the acquisition of OPI (see Note 2). There have been no other material changes to the Company's purchase obligations and other contractual obligations from those disclosed in its Annual Report on Form 10-K for the year ended December 31, 2019. Legal Matters From time to time, the Company may be subject to legal proceedings and claims in the ordinary course of business. As of September 30, 2020, and as of the filing of this Quarterly Report on Form 10-Q, the Company was not involved in any material legal proceedings.

Leases

Leases	9 Months Ended
	Sep. 30, 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 We lease real estate space under non-cancelable operating lease agreements for commercial and industrial space, as well as our corporate headquarters located in Vancouver, Washington. Our facilities-related operating leases have remaining terms of 0.3 to 14.7 years, and some leases include options to extend up to 15 years. We also have leases for automobiles, manufacturing and office and computer equipment with remaining lease terms of 0.2 to 5.7 years. These leases are primarily operating leases; financing leases are not material. We did not include any of our renewal options in our lease terms for calculating our lease liability as we are not reasonably certain we will exercise the options at this time. The weighted-average remaining lease term for our lease obligations was 9.0 years at September 30, 2020, and the weighted-average discount rate was 3.5%. The components of lease expense related to operating leases were as follows (in thousands): Three Months Ended Nine Months Ended Lease expense: Operating lease expense $ 758 $ 2,178 Short-term lease expense 35 153 Variable and other lease expense 128 381 $ 921 $ 2,712 Undiscounted future minimum payments under our non-cancelable lease obligations were as follows as of September 30, 2020 (in thousands): Remainder of 2020 $ 785 2021 2,463 2022 1,873 2023 1,401 2024 1,347 Thereafter 5,976 $ 13,845

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income Tax Provision To calculate the interim tax provision, at the end of each interim period the Company estimates the annual effective tax rate and applies that to its ordinary quarterly earnings. The effect of changes in the enacted tax laws or rates is recognized in the interim period in which the change occurs. The computation of the annual estimated effective tax rate at each interim period requires certain estimates and judgments including, but not limited to, the expected operating income for the year, projections of the proportion of income earned and taxed in foreign jurisdictions, permanent differences between book and tax amounts, and the likelihood of recovering deferred tax assets generated in the current year. The accounting estimates used to compute the provision for income taxes may change as new events occur, additional information is obtained, or the tax environment changes. The Company’s effective tax rate for the three and nine months ended September 30, 2020 and 2019 differs from the U.S. statutory rate due to the U.S. and China valuation allowance, foreign income taxed at local statutory rates, and accrued withholding taxes. In addition, the three and nine months ended September 30, 2020 included a $1.7 million prior year tax benefit true-up related to purchase accounting for Nutronics. For the nine months ended September 30, 2020, the Company reported U.S. pre-tax loss and China pre-tax income. The Company has not yet been able to establish a sustained level of profitability in the U.S. and China, or other sufficient significant positive evidence, to conclude that its U.S. and China deferred tax assets are more likely than not to be realized. Therefore, the Company continues to maintain a valuation allowance against its U.S. and China deferred tax assets.

Stockholders' Equity and Stock-

Stockholders' Equity and Stock-Based Compensation	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Stockholders' Equity and Stock-Based Compensation	Stockholders' Equity and Stock-Based Compensation Restricted Stock Awards and Units Restricted stock award (RSA) and restricted stock unit (RSU) activity under our 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 September 30, 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 1,150 21.60 Awards vested (400) 21.66 Awards forfeited (75) 20.19 RSUs at September 30, 2020 3,082 $ 19.96 The total fair value of RSAs and RSUs vested during the nine months ended September 30, 2020 was $1.5 million and $7.0 million, respectively. Awards outstanding as of September 30, 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 nine months ended September 30, 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 (633) $1.77 Options canceled (13) $1.56 Outstanding, September 30, 2020 3,593 $1.50 5.5 $78,962 Options exercisable at September 30, 2020 2,869 $1.06 5.2 $64,337 Options vested as of September 30, 2020 and expected to vest after September 30, 2020 3,593 $1.50 5.5 $78,962 Total intrinsic value of options exercised for the nine months ended September 30, 2020 and 2019 was $11.2 million and $11.5 million, respectively. The Company received proceeds of $1.1 million and $1.0 million from the exercise of options for the nine months ended September 30, 2020 and 2019, respectively. Employee Stock Purchase Plan Information related to activity under our Employee Stock Purchase Plan (ESPP) was as follows (in thousands, except weighted- average per share prices): Nine Months Ended September 30, 2020 Shares issued 39 Weighted-average per share purchase price $ 17.53 Weighted-average per share discount from the fair value of the Company's common stock on date of issuance $ 3.85 Stock-Based Compensation Total stock-based compensation expense was included in our consolidated statements of operations as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Cost of revenues $ 505 $ 340 $ 1,189 $ 816 Research and development 2,545 424 6,602 1,693 Sales, general and administrative 3,633 315 8,692 2,860 $ 6,683 $ 1,079 $ 16,483 $ 5,369 Unrecognized Compensation Costs As of September 30, 2020, total unrecognized stock-based compensation related to unvested stock awards was $64.9 million, which will be recognized over the next five years as follows (in thousands): Remainder of 2020 $ 6,594 2021 24,256 2022 19,231 2023 12,154 2024 2,646 $ 64,881 Total unrecognized stock-based compensation includes approximately 0.6 million awards that do not have a measurement date and have been valued as of September 30, 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. This program is intended to offset the potentially dilutive effects of restricted stock grants awarded in connection with the acquisition of Nutronics. (See Note 2 for additional information.) As of September 30, 2020, no repurchases had been executed under the program.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 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 period presented (dollars in thousands): Three Months Ended September 30, 2020 Laser Products Advanced Development Corporate and Other Totals Revenue $ 51,117 $ 10,615 $ — $ 61,732 Gross profit $ 16,977 $ 688 $ (505) $ 17,160 Gross margin 33.2 % 6.5 % NM 27.8 % Nine Months Ended September 30, 2020 Laser Products Advanced Development Corporate and Other Totals Revenue $ 133,151 $ 23,934 $ — $ 157,085 Gross profit $ 39,198 $ 1,708 $ (1,189) $ 39,717 Gross margin 29.4 % 7.1 % NM 25.3 % Corporate and Other is unallocated expenses related to stock-based compensation. Since the Company operated only in the Laser Products segment prior to the acquisition of Nutronics in November 2019, no comparative information is presented for 2019.

Net Loss per Share

Net Loss per Share	9 Months Ended
	Sep. 30, 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): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Numerator: Net loss $ (2,110) $ (778) $ (16,415) $ (2,168) Denominator: Weighted-average shares, basic 38,558 37,262 38,195 37,005 Weighted-average shares, diluted 38,558 37,262 38,195 37,005 Net loss per share: Basic $ (0.05) $ (0.02) $ (0.43) $ (0.06) Diluted $ (0.05) $ (0.02) $ (0.43) $ (0.06) 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): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Restricted stock units and awards 3,498 1,912 2,129 1,912 Employee stock purchase plan 39 33 — 77 Common stock options 3,593 4,529 3,593 4,529 7,130 6,474 5,722 6,518

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent Event On November 3, 2020, the Company entered into a lease amendment related to its Longmont, Colorado facilities. The agreement included lease modifications that extended the lease term on the Company's existing premises and added a new right-of-use asset consisting of additional expansion premises. The lease, as modified, includes a minimum lease term of 90 months. The lease modifications together resulted in increases to the Company's balance sheet of approximately $1.1 million each in right-of-use assets and lease liabilities as of the lease modification date.

Basis of Presentation and New_2

Basis of Presentation and New Accounting Pronouncements (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements of nLIGHT, Inc. and its wholly owned subsidiaries (Company) have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) and pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). The unaudited financial information reflects, in the opinion of management, all adjustments necessary for a fair presentation of financial position, results of operations, stockholders’ equity, and cash flows for the interim periods presented. The results reported for the interim period presented are not necessarily indicative of results that may be expected for the full year. These consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our 2019 Annual Report on Form 10-K.
Reclassifications	Reclassifications Certain immaterial reclassifications were made to the prior period financial statements to conform to the current period presentation.
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 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 annual reporting periods of emerging growth companies 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 is currently evaluating the impact on its consolidated financial statements and cannot reasonably estimate the impact on its financial statements at this time. ASU 2020-04 FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting,
Inventory	Inventory is stated at the lower of average cost and net realizable value.
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.

Acquisition (Tables)

Acquisition (Tables)	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Summary of Assets Acquired and Liabilities Assumed	The allocation of the purchase price for the OPI acquisition was as follows (in thousands): Valuation at July 30, 2020 Cash $ 58 Accounts receivable 73 Inventory 307 Other assets 186 Tangible assets acquired 624 Accounts payable (193) Deferred taxes (299) Debt (402) Other liabilities (164) Liabilities assumed (1,058) Total tangible assets and liabilities assumed (434) Intangible assets 1,179 Goodwill 869 Net assets acquired $ 1,614 Valuation as of Balances as of November 14, 2019 Adjustments September 30, 2020 Cash $ 33 $ — $ 33 Accounts receivable 635 — 635 Contract assets 456 — 456 Inventory 255 — 255 Other current assets 201 — 201 Property, plant and equipment 1,019 — 1,019 Security deposits 46 — 46 Tangible assets acquired 2,645 — 2,645 Accounts payable (278) — (278) Other liabilities (477) (100) (577) Deferred revenue (141) — (141) Deferred taxes — (1,667) (1,667) Liabilities assumed (896) (1,767) (2,663) Total tangible assets acquired and liabilities assumed 1,749 (1,767) (18) Intangible assets 7,200 7,200 Goodwill 8,484 1,767 10,251 Net assets acquired $ 17,433 $ — $ 17,433
Schedule of Finite-Lived Intangible Assets Acquired	The intangible assets as of the July 30, 2020 acquisition date were as follows (in thousands): Amount Weighted-Average Useful Life (in years) Developed technology $ 1,179 5.0 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)	9 Months Ended
	Sep. 30, 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 Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Industrial $ 21,880 $ 18,977 $ 60,500 $ 58,021 Microfabrication 14,052 13,280 38,771 45,907 Aerospace and Defense 25,800 11,557 57,814 29,795 $ 61,732 $ 43,814 $ 157,085 $ 133,723
Schedule of Sales by Geography	Sales by Geography Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 North America $ 31,384 $ 16,382 $ 72,924 $ 50,294 China 19,186 17,397 52,723 49,251 Rest of World 11,162 10,035 31,438 34,178 $ 61,732 $ 43,814 $ 157,085 $ 133,723
Schedule of Sales by Timing of Revenue	Sales by Timing of Revenue Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Point in time $ 51,101 $ 42,458 $ 133,304 $ 129,951 Over time 10,631 1,356 23,781 3,772 $ 61,732 $ 43,814 $ 157,085 $ 133,723
Schedule of Contract Assets and Liabilities	The Company's contract assets and liabilities are as follows (in thousands): Balance Sheet Classification As of September 30, 2020 December 31, 2019 Contract assets Prepaid expenses and other current assets $ 5,178 $ 2,449 Contract liabilities Deferred revenue and Other long-term liabilities 2,524 881

Concentrations of Credit and _2

Concentrations of Credit and Other Risks (Tables)	9 Months Ended
	Sep. 30, 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: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Quick Laser Technology Co., Ltd. 13% 12% 13% * U.S. Government 16% * 13% * Raytheon Technologies 12% 15% 13% 12%

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 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): September 30, 2020 Level 1 Level 2 Level 3 Total Money market securities $ 74,084 $ — $ — $ 74,084 Commercial paper 4,585 — — 4,585 Total $ 78,669 $ — $ — $ 78,669 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)	9 Months Ended
	Sep. 30, 2020
Inventory Disclosure [Abstract]
Schedule of Components of Inventory	Inventory consisted of the following (in thousands): As of September 30, 2020 December 31, 2019 Raw materials $ 19,740 $ 16,643 Work in process and semi-finished goods 22,693 17,723 Finished goods 10,999 11,765 $ 53,432 $ 46,131

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment	Property, plant and equipment consist of the following (in thousands): As of Useful life (years) September 30, 2020 December 31, 2019 Computer hardware and software 3-5 $ 4,625 $ 4,764 Manufacturing and lab equipment 2-7 65,893 59,395 Office equipment and furniture 5-7 1,410 1,462 Leasehold and building improvements 2-12 21,470 20,759 Buildings 30 9,081 — Land N/A 3,399 — 105,878 86,380 Accumulated depreciation (63,513) (58,633) $ 42,365 $ 27,747

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2020 December 31, 2019 Patents 3 - 5 $ 6,689 $ 5,956 Development programs 2 - 4 7,200 7,200 Developed technology 5 1,171 — 15,060 13,156 Accumulated amortization (5,972) (3,150) $ 9,088 $ 10,006
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 869 — 869 Purchase accounting adjustment — 1,767 1,767 Currency exchange rate adjustment (5) — (5) Balance, September 30, 2020 $ 2,252 $ 10,251 $ 12,503

Other Assets (Tables)

Other Assets (Tables)	9 Months Ended
	Sep. 30, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Other Assets	Other assets consisted of the following (in thousands): As of September 30, 2020 December 31, 2019 Demonstration assets, net $ 1,965 $ 1,824 Deferred tax assets, net 72 72 Other 2,644 1,811 $ 4,681 $ 3,707 Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Amortization expense $ 478 $ 454 $ 1,500 $ 1,355

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	9 Months Ended
	Sep. 30, 2020
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consist of the following (in thousands): As of September 30, 2020 December 31, 2019 Accrued payroll and benefits $ 10,759 $ 8,208 Product warranty, current 1,982 1,683 Income tax payable — 155 Other accrued expenses 1,922 1,559 $ 14,663 $ 11,605

Product Warranties (Tables)

Product Warranties (Tables)	9 Months Ended
	Sep. 30, 2020
Guarantees and Product Warranties [Abstract]
Schedule of Reconciliation of the Changes in the Aggregate Product Warranty Liability	Product warranty liability activity for the nine months ended September 30, 2020 and 2019 was as follows (in thousands): Nine Months Ended September 30, 2020 2019 Product warranty liability, beginning $ 2,984 $ 4,555 Warranty charges incurred, net (2,259) (1,971) Provision for warranty charges, net of adjustments 3,425 456 Acquired warranty 100 — Product warranty liability, ending $ 4,250 $ 3,040 Less: current portion of product warranty liability (1,982) (1,725) Non-current portion of product warranty liability $ 2,268 $ 1,315

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Schedule of Components of Lease Expense	The components of lease expense related to operating leases were as follows (in thousands): Three Months Ended Nine Months Ended Lease expense: Operating lease expense $ 758 $ 2,178 Short-term lease expense 35 153 Variable and other lease expense 128 381 $ 921 $ 2,712
Schedule of Future Minimum Payments Under Non-Cancelable Lease Obligations	uture minimum payments under our non-cancelable lease obligations were as follows as of September 30, 2020 (in thousands): Remainder of 2020 $ 785 2021 2,463 2022 1,873 2023 1,401 2024 1,347 Thereafter 5,976 $ 13,845

Stockholders' Equity and Stoc_2

Stockholders' Equity and Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Schedule of Restricted Stock Awards and Units	Restricted stock award (RSA) and restricted stock unit (RSU) activity under our 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 September 30, 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 1,150 21.60 Awards vested (400) 21.66 Awards forfeited (75) 20.19 RSUs at September 30, 2020 3,082 $ 19.96
Schedule of Stock Option Activity	The following table summarizes the Company’s stock option activity during the nine months ended September 30, 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 (633) $1.77 Options canceled (13) $1.56 Outstanding, September 30, 2020 3,593 $1.50 5.5 $78,962 Options exercisable at September 30, 2020 2,869 $1.06 5.2 $64,337 Options vested as of September 30, 2020 and expected to vest after September 30, 2020 3,593 $1.50 5.5 $78,962
Schedule of Employee Stock Purchase Plan	Information related to activity under our Employee Stock Purchase Plan (ESPP) was as follows (in thousands, except weighted- average per share prices): Nine Months Ended September 30, 2020 Shares issued 39 Weighted-average per share purchase price $ 17.53 Weighted-average per share discount from the fair value of the Company's common stock on date of issuance $ 3.85
Schedule of Stock-based Compensation Expense	Total stock-based compensation expense was included in our consolidated statements of operations as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Cost of revenues $ 505 $ 340 $ 1,189 $ 816 Research and development 2,545 424 6,602 1,693 Sales, general and administrative 3,633 315 8,692 2,860 $ 6,683 $ 1,079 $ 16,483 $ 5,369
Schedule of Share-Based Payment Arrangement, Nonvested Award, Cost	As of September 30, 2020, total unrecognized stock-based compensation related to unvested stock awards was $64.9 million, which will be recognized over the next five years as follows (in thousands): Remainder of 2020 $ 6,594 2021 24,256 2022 19,231 2023 12,154 2024 2,646 $ 64,881

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Summary of Operating Results by Reportable Segment	The following table summarizes the operating results by reportable segment for the period presented (dollars in thousands): Three Months Ended September 30, 2020 Laser Products Advanced Development Corporate and Other Totals Revenue $ 51,117 $ 10,615 $ — $ 61,732 Gross profit $ 16,977 $ 688 $ (505) $ 17,160 Gross margin 33.2 % 6.5 % NM 27.8 % Nine Months Ended September 30, 2020 Laser Products Advanced Development Corporate and Other Totals Revenue $ 133,151 $ 23,934 $ — $ 157,085 Gross profit $ 39,198 $ 1,708 $ (1,189) $ 39,717 Gross margin 29.4 % 7.1 % NM 25.3 %

Net Loss per Share (Tables)

Net Loss per Share (Tables)	9 Months Ended
	Sep. 30, 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): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Numerator: Net loss $ (2,110) $ (778) $ (16,415) $ (2,168) Denominator: Weighted-average shares, basic 38,558 37,262 38,195 37,005 Weighted-average shares, diluted 38,558 37,262 38,195 37,005 Net loss per share: Basic $ (0.05) $ (0.02) $ (0.43) $ (0.06) Diluted $ (0.05) $ (0.02) $ (0.43) $ (0.06)
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): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Restricted stock units and awards 3,498 1,912 2,129 1,912 Employee stock purchase plan 39 33 — 77 Common stock options 3,593 4,529 3,593 4,529 7,130 6,474 5,722 6,518

Basis of Presentation and New_3

Basis of Presentation and New Accounting Pronouncements - New Accounting Pronouncements (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2018	Jan. 01, 2020
Accounting Policies [Abstract]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member	us-gaap:AccountingStandardsUpdate201807Member
Lease right-of-use assets	$ 11,428		$ 7,600
Operating lease liabilities			$ 7,900

Acquisition - Narrative (Detail

Acquisition - Narrative (Details) - USD ($) $ in Thousands	Jul. 30, 2020	Nov. 14, 2019	Sep. 30, 2020	Sep. 30, 2020
OPI Photonics
Business Acquisition [Line Items]
Acquisition consideration, cash	$ 1,600
Acquisition contingent consideration	300
Acquisition paid	$ 200
Remaining amount			$ 1,400
Payment period	24 months
Transaction costs			$ 100	$ 100
Nutronics, Inc.
Business Acquisition [Line Items]
Acquisition consideration, cash		$ 17,400
Increase to deferred taxes and other liabilities acquired				$ (1,767)

Acquisition - Assets Acquired a

Acquisition - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	9 Months Ended	11 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Jul. 30, 2020	Dec. 31, 2019	Nov. 14, 2019
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Goodwill	$ 12,503	$ 12,503		$ 9,872
Goodwill	1,767
OPI Photonics
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Cash			$ 58
Accounts receivable			73
Inventory			307
Other assets			186
Tangible assets acquired			624
Accounts payable			(193)
Other liabilities			(164)
Debt			(402)
Deferred taxes			(299)
Liabilities assumed			(1,058)
Total tangible assets acquired and liabilities assumed			(434)
Intangible assets			1,179
Goodwill			869
Net assets acquired			$ 1,614
Nutronics, Inc.
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Cash	33	33			$ 33
Accounts receivable	635	635			635
Contract assets	456	456			456
Inventory	255	255			255
Other current assets	201	201			201
Property, plant and equipment	1,019	1,019			1,019
Security deposits	46	46			46
Tangible assets acquired	2,645	2,645			2,645
Accounts payable	(278)	(278)			(278)
Other liabilities	(577)	(577)			(477)
Other liabilities		(100)
Deferred revenue	(141)	(141)			(141)
Deferred taxes	(1,667)	(1,667)			0
Deferred taxes		(1,667)
Liabilities assumed	(2,663)	(2,663)			(896)
Liabilities assumed		(1,767)
Total tangible assets acquired and liabilities assumed	(18)	(18)			1,749
Total tangible assets acquired and liabilities assumed		(1,767)
Intangible assets	7,200	7,200			7,200
Goodwill	10,251	10,251			8,484
Goodwill		1,767
Net assets acquired	$ 17,433	$ 17,433			$ 17,433

Acquisition - Intangible Assets

Acquisition - Intangible Assets (Details) - USD ($) $ in Thousands	Jul. 30, 2020	Nov. 14, 2019	Sep. 30, 2020
OPI Photonics
Business Acquisition [Line Items]
Amount	$ 1,179
OPI Photonics | Development programs
Business Acquisition [Line Items]
Amount	$ 1,179
Weighted-Average Useful Life (in years)	5 years
Nutronics, Inc.
Business Acquisition [Line Items]
Amount		$ 7,200	$ 7,200
Nutronics, Inc. | 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	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 61,732	$ 43,814	$ 157,085	$ 133,723
Point in time
Disaggregation of Revenue [Line Items]
Total revenue	51,101	42,458	133,304	129,951
Over time
Disaggregation of Revenue [Line Items]
Total revenue	10,631	1,356	23,781	3,772
North America
Disaggregation of Revenue [Line Items]
Total revenue	31,384	16,382	72,924	50,294
China
Disaggregation of Revenue [Line Items]
Total revenue	19,186	17,397	52,723	49,251
Rest of World
Disaggregation of Revenue [Line Items]
Total revenue	11,162	10,035	31,438	34,178
Industrial
Disaggregation of Revenue [Line Items]
Total revenue	21,880	18,977	60,500	58,021
Microfabrication
Disaggregation of Revenue [Line Items]
Total revenue	14,052	13,280	38,771	45,907
Aerospace and Defense
Disaggregation of Revenue [Line Items]
Total revenue	$ 25,800	$ 11,557	$ 57,814	$ 29,795

Revenue - Contract Assets and L

Revenue - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Contract assets	$ 5,178	$ 2,449
Contract liabilities	$ 2,524	$ 881

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue recognized, previously included in customer advances and deferred revenue	$ 0.8	$ 1.6

Concentrations of Credit and _3

Concentrations of Credit and Other Risks (Details) - Customer Concentration Risk	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Sales Revenue | Quick Laser Technology Co., Ltd.
Concentration Risk [Line Items]
Concentration risk, percentage	13.00%	12.00%	13.00%
Sales Revenue | U.S. Government
Concentration Risk [Line Items]
Concentration risk, percentage	16.00%		13.00%
Sales Revenue | Raytheon Technologies
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%	15.00%	13.00%	12.00%
Accounts receivable | One Customer
Concentration Risk [Line Items]
Concentration risk, percentage			44.00%
Accounts receivable | Two Customers
Concentration Risk [Line Items]
Concentration risk, percentage					48.00%

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	$ 78,669	$ 96,661
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	78,669	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	4,585	2,401
Commercial paper | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	4,585	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	Sep. 30, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Raw materials	$ 19,740	$ 16,643
Work in process and semi-finished goods	22,693	17,723
Finished goods	10,999	11,765
Inventory	$ 53,432	$ 46,131

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) ft² in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)	Jun. 30, 2020abuilding	Mar. 31, 2020ft²	Dec. 31, 2019USD ($)
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 105,878			$ 86,380
Accumulated depreciation	(63,513)			(58,633)
Property and equipment, net	42,365			27,747
Computer hardware and software
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 4,625			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	$ 65,893			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	$ 1,410			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	$ 21,470			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	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 15,060	$ 13,156
Accumulated amortization	(5,972)	(3,150)
Net value	9,088	10,006
Patents
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	6,689	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	$ 1,171	$ 0
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 | 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 - Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Goodwill [Roll Forward]
Goodwill	$ 9,872
Business acquisition	869
Purchase accounting adjustment	1,767
Currency exchange rate adjustment	(5)
Goodwill	12,503
Laser Products
Goodwill [Roll Forward]
Goodwill	1,388
Business acquisition	869
Purchase accounting adjustment	0
Currency exchange rate adjustment	(5)
Goodwill	2,252
Advanced Development
Goodwill [Roll Forward]
Goodwill	8,484
Business acquisition	0
Purchase accounting adjustment	1,767
Currency exchange rate adjustment	0
Goodwill	$ 10,251

Other Assets (Details)

Other Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Other Assets, Noncurrent Disclosure [Abstract]
Demonstration assets, net	$ 1,965		$ 1,965		$ 1,824
Deferred tax assets, net	72		72		72
Other	2,644		2,644		1,811
Other assets	4,681		$ 4,681		$ 3,707
Useful life of demonstration assets			2 years
Amortization expense	$ 478	$ 454	$ 1,500	$ 1,355

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued payroll and benefits	$ 10,759	$ 8,208
Product warranty, current	1,982	1,683
Income tax payable	0	155
Other accrued expenses	1,922	1,559
Total accrued liabilities	$ 14,663	$ 11,605

Product Warranties (Details)

Product Warranties (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Movement in Standard Product Warranty Accrual [Roll Forward]
Product warranty liability, beginning	$ 2,984	$ 4,555
Warranty charges incurred, net	(2,259)	(1,971)
Provision for warranty charges, net of adjustments	3,425	456
Acquired warranty	100	0
Product warranty liability, ending	4,250	3,040
Less: current portion of product warranty liability	(1,982)	(1,725)
Non-current portion of product warranty liability	$ 2,268	$ 1,315

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details)	9 Months Ended
	Sep. 30, 2020USD ($)
OPI Photonics
Line of Credit Facility [Line Items]
Contractual obligation	$ 11,700,000
Remaining amount	1,400,000
Revolving credit facility | Line of credit
Line of Credit Facility [Line Items]
Revolving line of credit, borrowing capacity	$ 40,000,000
Unused credit fee (percent)	0.20%
Outstanding	$ 0

Leases - Narrative (Details)

Leases - Narrative (Details)	Sep. 30, 2020
Lessee, Lease, Description [Line Items]
Weighted-average remaining lease term for operating leases	9 years
Weighted-average discount rate for operating leases	3.50%
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	3 months 18 days
Operating Leases, Excluding Automobiles | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	14 years 8 months 12 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 8 months 12 days

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Leases [Abstract]
Operating lease expense	$ 758	$ 2,178
Short-term lease expense	35	153
Variable and other lease expense	128	381
Lease expense	$ 921	$ 2,712

Leases - Future Minimum Payment

Leases - Future Minimum Payments Under Non-Cancelable Operating Leases (Details) $ in Thousands	Sep. 30, 2020USD ($)
Leases [Abstract]
Remainder of 2020	$ 785
2021	2,463
2022	1,873
2023	1,401
2024	1,347
Thereafter	5,976
Total	$ 13,845

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Prior year tax benefit true-up	$ 1.7	$ 1.7

Stockholders' Equity and Stoc_3

Stockholders' Equity and Stock-Based Compensation - Summary of Restricted Stock Award and Restricted Stock Unit Activity (Details) shares in Thousands	9 Months Ended
	Sep. 30, 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	1,150
Vested (in shares) | shares	(400)
Forfeited & modified (in shares) | shares	(75)
Balance, ending (in shares) | shares	3,082
Weighted average exercise price
Balance, beginning (in dollars per share) | $ / shares	$ 19.47
Granted (in dollars per share) | $ / shares	21.60
Vested (in dollars per share) | $ / shares	21.66
Forfeited & modified (in dollars per share) | $ / shares	20.19
Balance, ending (in dollars per share) | $ / shares	$ 19.96

Stockholders' Equity and Stoc_4

Stockholders' Equity and Stock-Based Compensation - Narrative (Details) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Nov. 14, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised	$ 11,200,000	$ 11,500,000
Proceeds from the exercise of options	1,117,000	$ 1,032,000
Unrecognized expense	$ 64,900,000
Authorized repurchase amount				$ 10,000,000
Number of shares repurchased (in shares)	0
Restricted Stock Awards (RSAs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, fair value	$ 1,500,000
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	$ 7,000,000
Awards outstanding (in shares)	3,082,000		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

Stockholders' Equity and Stoc_5

Stockholders' Equity and Stock-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares
Number of shares
Outstanding, beginning of period (in shares) | shares	4,239
Options exercised (in shares) | shares	(633)
Options canceled (in shares) | shares	(13)
Outstanding, end of period (in shares) | shares	3,593	4,239
Weighted average exercise price
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 1.54
Options exercised (in dollars per share) | $ / shares	1.77
Options canceled (in dollars per share) | $ / shares	1.56
Outstanding, end of period (in dollars per share) | $ / shares	$ 1.50	$ 1.54
Outstanding, Weighted average remaining contractual term (years)	5 years 6 months	6 years 1 month 6 days
Outstanding, Aggregate intrinsic value | $	$ 78,962	$ 79,443
Options exercisable at end of period
Options exercisable (in shares) | shares	2,869
Weighted average exercise price (in dollars per share) | $ / shares	$ 1.06
Weighted average remaining contractual term (years)	5 years 2 months 12 days
Aggregate intrinsic value | $	$ 64,337
Options vested as of end of period and expected to vest after end of period
Options vested and expected to vest (in shares) | shares	3,593
Weighted average exercise price (in dollars per share) | $ / shares	$ 1.50
Weighted Average Remaining Contractual Term (Years)	5 years 6 months
Aggregate Intrinsic Value | $	$ 78,962

Stockholders' Equity and Stoc_6

Stockholders' Equity and Stock-Based Compensation - Employee Stock Purchase Program (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Equity [Abstract]
Shares issued (in shares) | shares	39
Weighted average per share purchase price (in dollars per share)	$ 17.53
Weighted average per share discount from the fair value of our common stock on date of issuance (in dollars per share)	$ 3.85

Stockholders' Equity and Stoc_7

Stockholders' Equity and Stock-Based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 6,683	$ 1,079	$ 16,483	$ 5,369
Cost of revenues
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	505	340	1,189	816
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	2,545	424	6,602	1,693
Sales, general and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 3,633	$ 315	$ 8,692	$ 2,860

Stockholders' Equity and Stoc_8

Stockholders' Equity and Stock-Based Compensation - Unrecognized Compensation Costs (Details) $ in Thousands	Sep. 30, 2020USD ($)
Equity [Abstract]
Remainder of 2020	$ 6,594
2021	24,256
2022	19,231
2023	12,154
2024	2,646
Total compensation cost	$ 64,881

Segment Information - Narrative

Segment Information - Narrative (Details)	9 Months Ended
	Sep. 30, 2020segment
Segment Reporting [Abstract]
Number of reportable segments	2

Segment Information - Operating

Segment Information - Operating Results (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Revenue	$ 61,732	$ 43,814	$ 157,085	$ 133,723
Gross profit	$ 17,160	$ 12,962	$ 39,717	$ 42,347
Gross margin	27.80%		25.30%
Operating segments | Laser Products
Segment Reporting Information [Line Items]
Revenue	$ 51,117		$ 133,151
Gross profit	$ 16,977		$ 39,198
Gross margin	33.20%		29.40%
Operating segments | Advanced Development
Segment Reporting Information [Line Items]
Revenue	$ 10,615		$ 23,934
Gross profit	$ 688		$ 1,708
Gross margin	6.50%		7.10%
Corporate and Other
Segment Reporting Information [Line Items]
Revenue	$ 0		$ 0
Gross profit	$ (505)		$ (1,189)

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	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net loss	$ (2,110)	$ (778)	$ (16,415)	$ (2,168)
Denominator:
Weighted-average shares, basic (in shares)	38,558	37,262	38,195	37,005
Weighted-average shares, diluted (in shares)	38,558	37,262	38,195	37,005
Net loss per share:
Basic (in dollars per share)	$ (0.05)	$ (0.02)	$ (0.43)	$ (0.06)
Diluted (in dollars per share)	$ (0.05)	$ (0.02)	$ (0.43)	$ (0.06)

Net Loss per Share - Antidiluti

Net Loss per Share - Antidilutive Securities Excluded from Dilutive Shares (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	7,130	6,474	5,722	6,518
Restricted stock units and awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	3,498	1,912	2,129	1,912
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	39	33	0	77
Common stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	3,593	4,529	3,593	4,529

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Thousands	Nov. 03, 2020	Sep. 30, 2020	Jan. 01, 2020
Subsequent Event [Line Items]
Right-of-use assets		$ 11,428	$ 7,600
Operating lease liabilities			$ 7,900
Longmont, Colorado Facility | Subsequent Event
Subsequent Event [Line Items]
Minimum lease term	90 months
Right-of-use assets	$ 1,100
Operating lease liabilities	$ 1,100