Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include the accounts of nLIGHT, Inc. and our wholly owned subsidiaries Arbor Photonics, LLC, nLIGHT Cayman Ltd., nLIGHT Laser Technology (Shanghai) Co. Ltd, nLIGHT Oy (Finland), nLIGHT Korea Inc., nLIGHT GmbH, nLIGHT DEFENSE Systems Inc. (fka Nutronics, Inc.), and nLIGHT Europe 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 in the United States of America (GAAP) 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, we evaluate our estimates, including those related to inventory valuation, allowances for doubtful accounts, warranty, sales return reserves and the recoverability of long-lived assets. Management bases its estimates on historical experience and on various other assumptions. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents We consider all highly liquid investments with an original maturity of three months or less when acquired to be cash equivalents.Cash equivalents are carried at cost, which approximates fair value.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are stated at cost, net of accumulated depreciation. 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 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. We perform 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. During the fourth quarter of 2024, we performed a quantitative test to determine if impairment existed. The fair values of our reporting units were determined using a weighted average of a market approach and an income approach. Under the market approach, fair values were estimated using published market multiples for comparable companies. We calculated fair values under the income approach by taking estimated future cash flows that are based on internal projections and other assumptions deemed reasonable by management and discounted them using an estimated weighted average cost of capital.
Intangible Assets	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.
Restructuring Charges	Restructuring Charges Restructuring charges in 2024 and 2023 were comprised primarily of employee severance. The determination of when we accrue for employee termination benefits depends on whether the termination benefits are provided under a one-time benefit arrangement or under an on-going benefit arrangement. For restructuring charges recorded as an on-going benefit arrangement, a liability for post-employment benefits is recorded when payment is probable, the amount is reasonably estimable, and the obligation relates to rights that have vested or accumulated. For restructuring charges recorded as a one-time benefit arrangement, we recognize a liability for employee termination benefits when a plan of termination, approved by management and establishing the terms of the benefit arrangement, has been communicated to employees. The timing of the recognition of one-time employee termination benefits is dependent upon the period of time the employees are required to render service after communication. If employees are not required to render service in order to receive the termination benefits or if employees will not be retained to render service beyond the minimum legal notification period, a liability for the termination benefits is recognized at the communication date. In instances where employees will be retained to render service beyond the minimum legal notification period, the liability for employee termination benefits is measured initially at the communication date based on the fair value of the liability as of the termination date and is recognized ratably over the future service period. We continually evaluate the adequacy of the remaining liabilities under our restructuring initiatives. We record charges related to long-lived assets to be abandoned when the assets cease to be used, and any inventory charges related to restructuring are classified as a cost of revenue. Although we believe that these estimates accurately reflect the costs of our restructuring plans, actual results may differ, thereby requiring us to record additional provisions or reverse a portion of such provisions.
Impairment of Long-Lived Assets	Impairment of Long‑Lived Assets Long‑lived assets, such as property, plant and equipment and intangible assets 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.
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.
Stock‑Based Compensation	Stock-Based Compensation We recognize compensation expense for stock-based awards on a straight-line basis based on the grant-date estimated fair values and requisite service period. The fair value of stock options is measured using the Black-Scholes option pricing model, while the fair value of restricted stock units (RSU) and restricted stock awards (RSA) are measured based on the closing market price of our common stock on the date of grant. The fair value of restricted stock awards based on certain market performance criteria is measured using the Monte Carlo simulation pricing model.
Income Taxes	Income Taxes We account 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. We recognize 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 Currencies Our 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 income, net within the Consolidated Statements of Operations.
New Accounting Pronouncements	New Accounting Pronouncements ASU 2023-07 In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2023-07, Improvements to Reportable Segment Disclosures. The amendments in this ASU are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. We adopted ASU 2023-07 on December 31, 2024 using a retrospective transition method. The adoption did not have a material impact on our financial position, results of operations or cash flows. See Note 18, Segment Information, for additional information. ASU 2023-09 In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures. This ASU requires enhanced jurisdictional and other disaggregated disclosures for the effective tax rate reconciliation and income taxes paid and is effective for fiscal years beginning after December 15, 2024. This ASU requires additional disclosures and, accordingly, we do not expect the adoption of ASU 2023-09 to have a material effect on our financial position, results of operations or cash flows. ASU 2024-03 In November 2024, the FASB issued ASU 2024-03 related to the disaggregation of certain income statement expenses. The amendments in this update require public entities to disclose incremental information related to purchases of inventory, team member compensation and depreciation, which will provide investors the ability to better understand entity expenses and make their own judgements about entity performance. The amendments in this update are effective for fiscal years beginning after December 15, 2026. We plan to adopt this pronouncement and make the necessary updates to our disclosures for the year ending December 31, 2027, and, aside from these disclosure changes, we do not expect the amendments to have a material effect on our financial position, results of operations or cash flows.
Revenue Recognition	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.
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.
Product Warranties	We provide warranties on certain products and record 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 our estimate of future costs. The current portion of our product warranty liability is included in the accrued liabilities and the long-term portion is included in Other long-term liabilities in our Consolidated Balance Sheets.

Basis of Presentation and Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2024

The accompanying consolidated financial statements include the accounts of nLIGHT, Inc. and our wholly owned subsidiaries Arbor Photonics, LLC, nLIGHT Cayman Ltd., nLIGHT Laser Technology (Shanghai) Co. Ltd, nLIGHT Oy (Finland), nLIGHT Korea Inc., nLIGHT GmbH, nLIGHT DEFENSE Systems Inc. (fka Nutronics, Inc.), and nLIGHT Europe 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 in the United States of America (GAAP) 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, we evaluate our estimates, including those related to inventory valuation, allowances for doubtful accounts, warranty, sales return reserves and the recoverability of long-lived assets. Management bases its estimates on historical experience and on various other assumptions. Actual results could differ from those estimates.

Cash and Cash Equivalents

We consider all highly liquid investments with an original maturity of three months or less when acquired to be cash equivalents.Cash equivalents are carried at cost, which approximates fair value.

Property, Plant and Equipment

Property, plant and equipment are stated at cost, net of accumulated depreciation. 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 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. We perform 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.

During the fourth quarter of 2024, we performed a quantitative test to determine if impairment existed. The fair values of our reporting units were determined using a weighted average of a market approach and an income approach. Under the market approach, fair values were estimated using published market multiples for comparable companies. We calculated fair values under the income approach by taking estimated future cash flows that are based on internal projections and other assumptions deemed reasonable by management and discounted them using an estimated weighted average cost of capital.

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.

Restructuring Charges

Restructuring charges in 2024 and 2023 were comprised primarily of employee severance.

The determination of when we accrue for employee termination benefits depends on whether the termination benefits are provided under a one-time benefit arrangement or under an on-going benefit arrangement. For restructuring charges recorded as an on-going benefit arrangement, a liability for post-employment benefits is recorded when payment is probable, the amount is reasonably estimable, and the obligation relates to rights that have vested or accumulated. For restructuring charges recorded as a one-time benefit arrangement, we recognize a liability for employee termination benefits when a plan of termination, approved by management and establishing the terms of the benefit arrangement, has been communicated to employees. The timing of the recognition of one-time employee termination benefits is dependent upon the period of time the employees are required to render service after communication. If employees are not required to render service in order to receive the termination benefits or if employees will not be retained to render service beyond the minimum legal notification period, a liability for the termination benefits is recognized at the communication date. In instances where employees will be retained to render service beyond the minimum legal notification period, the liability for employee termination benefits is measured initially at the communication date based on the fair value of the liability as of the termination date and is recognized ratably over the future service period. We continually evaluate the adequacy of the remaining liabilities under our restructuring initiatives.

We record charges related to long-lived assets to be abandoned when the assets cease to be used, and any inventory charges related to restructuring are classified as a cost of revenue.

Although we believe that these estimates accurately reflect the costs of our restructuring plans, actual results may differ, thereby requiring us to record additional provisions or reverse a portion of such provisions.

Impairment of Long-Lived Assets

Impairment of Long‑Lived Assets

Long‑lived assets, such as property, plant and equipment and intangible assets 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.

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.

Stock‑Based Compensation

Stock-Based Compensation

We recognize compensation expense for stock-based awards on a straight-line basis based on the grant-date estimated fair values and requisite service period. The fair value of stock options is measured using the Black-Scholes option pricing model, while the fair value of restricted stock units (RSU) and restricted stock awards (RSA) are measured based on the closing market price of our common stock on the date of grant. The fair value of restricted stock awards based on certain market performance criteria is measured using the Monte Carlo simulation pricing model.

Income Taxes

We account 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.

We recognize 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

Our 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 income, net within the Consolidated Statements of Operations.

New Accounting Pronouncements

ASU 2023-07

In November 2023, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2023-07, Improvements to Reportable Segment Disclosures. The amendments in this ASU are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. We adopted ASU 2023-07 on December 31, 2024 using a retrospective transition method. The adoption did not have a material impact on our financial position, results of operations or cash flows. See Note 18, Segment Information, for additional information.

ASU 2023-09

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures. This ASU requires enhanced jurisdictional and other disaggregated disclosures for the effective tax rate reconciliation and income taxes paid and is effective for fiscal years beginning after December 15, 2024. This ASU requires additional disclosures and, accordingly, we do not expect the adoption of ASU 2023-09 to have a material effect on our financial position, results of operations or cash flows.

ASU 2024-03

In November 2024, the FASB issued ASU 2024-03 related to the disaggregation of certain income statement expenses. The amendments in this update require public entities to disclose incremental information related to

purchases of inventory, team member compensation and depreciation, which will provide investors the ability to better understand entity expenses and make their own judgements about entity performance. The amendments in this update are effective for fiscal years beginning after December 15, 2026. We plan to adopt this pronouncement and make the necessary updates to our disclosures for the year ending December 31, 2027, and, aside from these disclosure changes, we do not expect the amendments to have a material effect on our financial position, results of operations or cash flows.

Revenue Recognition

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.

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.

Product Warranties

We provide warranties on certain products and record 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 our estimate of future costs. The current portion of our product warranty liability is included in the accrued liabilities and the long-term portion is included in Other long-term liabilities in our Consolidated Balance Sheets.