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      <link:roleType id="LeasesFutureLeasePaymentsDetails" roleURI="http://lunainc.com/role/LeasesFutureLeasePaymentsDetails">
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        <link:usedOn>link:calculationLink</link:usedOn>
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      <link:roleType id="LeasesFutureLeasePaymentsDetailsCalc2" roleURI="http://lunainc.com/role/LeasesFutureLeasePaymentsDetailsCalc2">
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        <link:definition>2410403 - Disclosure - Leases - Lease Components (Details)</link:definition>
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        <link:usedOn>link:calculationLink</link:usedOn>
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      <link:roleType id="LeasesOtherLeaseInformationDetails" roleURI="http://lunainc.com/role/LeasesOtherLeaseInformationDetails">
        <link:definition>2410407 - Disclosure - Leases - Other Lease Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
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      <link:roleType id="LeasesRentExpenseDetails" roleURI="http://lunainc.com/role/LeasesRentExpenseDetails">
        <link:definition>2410404 - Disclosure - Leases - Rent Expense (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
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      <link:roleType id="LeasesTables" roleURI="http://lunainc.com/role/LeasesTables">
        <link:definition>2310301 - Disclosure - Leases (Tables)</link:definition>
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      <link:roleType id="OrganizationAndSummaryOfSignificantAccountingPolicies" roleURI="http://lunainc.com/role/OrganizationAndSummaryOfSignificantAccountingPolicies">
        <link:definition>2101100 - Disclosure - Organization and Summary of Significant Accounting Policies</link:definition>
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        <link:usedOn>link:calculationLink</link:usedOn>
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        <link:definition>2401403 - Disclosure - Organization and Summary of Significant Accounting Policies - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
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        <link:definition>2201201 - Disclosure - Organization and Summary of Significant Accounting Policies (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
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      <link:roleType id="OrganizationAndSummaryOfSignificantAccountingPoliciesPropertyAndEquipmentEstimatedUsefulLivesDetails" roleURI="http://lunainc.com/role/OrganizationAndSummaryOfSignificantAccountingPoliciesPropertyAndEquipmentEstimatedUsefulLivesDetails">
        <link:definition>2401404 - Disclosure - Organization and Summary of Significant Accounting Policies - Property and Equipment Estimated Useful Lives (Details)</link:definition>
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        <link:definition>2401405 - Disclosure - Organization and Summary of Significant Accounting Policies - Schedule of the Cumulative Effect of Adoption of Topic 842 (Details)</link:definition>
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      <link:roleType id="QuarterlyResultsUnauditedTables" roleURI="http://lunainc.com/role/QuarterlyResultsUnauditedTables">
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        <link:usedOn>link:calculationLink</link:usedOn>
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        <link:definition>2111100 - Disclosure - Stockholders' Equity</link:definition>
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        <link:definition>2411406 - Disclosure - Stockholders' Equity - Activity of Restricted Stock Issuances (Details)</link:definition>
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        <link:definition>2411407 - Disclosure - Stockholders' Equity - Activity of Restricted Stock Units (Details)</link:definition>
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        <link:definition>2411405 - Disclosure - Stockholders' Equity - Activity of Stock Option by Exercise Price Range (Details)</link:definition>
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        <link:definition>2411403 - Disclosure - Stockholders' Equity - Activity of Stock Options (Details)</link:definition>
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        <link:definition>2411402 - Disclosure - Stockholders' Equity - Additional Information (Details)</link:definition>
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        <link:definition>2411404 - Disclosure - Stockholders' Equity - Assumptions Used to Estimate Fair Value of Options Granted (Details)</link:definition>
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        <link:definition>2411408 - Disclosure - Stockholders' Equity - Share Repurchase Program (Details)</link:definition>
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        <link:definition>2311301 - Disclosure - Stockholders' Equity (Tables)</link:definition>
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  <xsd:element abstract="true" id="luna_DeferredIncomeTaxAssetsAndLiabilitiesLineItems" name="DeferredIncomeTaxAssetsAndLiabilitiesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_DeferredIncomeTaxAssetsAndLiabilitiesTable" name="DeferredIncomeTaxAssetsAndLiabilitiesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_DeferredTaxAssetsOperatingLeaseLiability" name="DeferredTaxAssetsOperatingLeaseLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="luna_DeferredTaxAssetsRestrictedStock" name="DeferredTaxAssetsRestrictedStock" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="luna_DeferredTaxAssetsTransactionCostsNoncurrent" name="DeferredTaxAssetsTransactionCostsNoncurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="luna_DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets" name="DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="luna_DisposalGroupIncludingDiscontinuedOperationAssetsHeldForSaleAdjustments" name="DisposalGroupIncludingDiscontinuedOperationAssetsHeldForSaleAdjustments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="luna_DisposalGroupIncludingDiscontinuedOperationConsiderationEscrow" name="DisposalGroupIncludingDiscontinuedOperationConsiderationEscrow" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="luna_DisposalGroupIncludingDiscontinuedOperationConsiderationGross" name="DisposalGroupIncludingDiscontinuedOperationConsiderationGross" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="luna_DisposalGroupIncludingDiscontinuedOperationContingentConsideration" name="DisposalGroupIncludingDiscontinuedOperationContingentConsideration" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="luna_DisposalGroupIncludingDiscontinuedOperationIntangiblePropertyCosts" name="DisposalGroupIncludingDiscontinuedOperationIntangiblePropertyCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="luna_DisposalGroupIncludingDiscontinuedOperationLiabilitiesHeldForSaleAdjustments" name="DisposalGroupIncludingDiscontinuedOperationLiabilitiesHeldForSaleAdjustments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="luna_DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense" name="DisposalGroupIncludingDiscontinuedOperationOtherIncomeExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="luna_DisposalGroupIncludingDiscontinuedOperationReturnOfWorkingCapital" name="DisposalGroupIncludingDiscontinuedOperationReturnOfWorkingCapital" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="luna_DisposalGroupIncludingDiscontinuedOperationTransactionCostAdjustments" name="DisposalGroupIncludingDiscontinuedOperationTransactionCostAdjustments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="luna_DisposalGroupIncludingDiscontinuedOperationsPurchasePriceReleasedFromEscrow" name="DisposalGroupIncludingDiscontinuedOperationsPurchasePriceReleasedFromEscrow" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="luna_DividendOnPreferredStockValueOfCommonStockIssuable" name="DividendOnPreferredStockValueOfCommonStockIssuable" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_DocumentAndEntityInformationAbstract" name="DocumentAndEntityInformationAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_EarningsPerShareFromContinuingOperationsAbstract" name="EarningsPerShareFromContinuingOperationsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_EarningsPerShareFromDiscontinuedOperationsAbstract" name="EarningsPerShareFromDiscontinuedOperationsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_EffectiveIncomeTaxRateReconciliationAlternativeMinimumTaxCarryoverPercent" name="EffectiveIncomeTaxRateReconciliationAlternativeMinimumTaxCarryoverPercent" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_EffectiveIncomeTaxRateReconciliationPermanentDifferences" name="EffectiveIncomeTaxRateReconciliationPermanentDifferences" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_EmployeesMember" name="EmployeesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_ExercisePriceRangeOneMember" name="ExercisePriceRangeOneMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_ExercisePriceRangeTwoMember" name="ExercisePriceRangeTwoMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_FinanceLeaseCost" name="FinanceLeaseCost" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_ForeignCommercialSalesAndOtherMember" name="ForeignCommercialSalesAndOtherMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_GeneralPhotonicsInc.Member" name="GeneralPhotonicsInc.Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_HighSpeedOpticalReceiversBusinessMember" name="HighSpeedOpticalReceiversBusinessMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_IncomeTaxesLineItems" name="IncomeTaxesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_IncomeTaxesTable" name="IncomeTaxesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_LeaseLiability" name="LeaseLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="luna_LeaseRightOfUseAsset" name="LeaseRightOfUseAsset" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="luna_MacomTechnologySolutionsInc.Member" name="MacomTechnologySolutionsInc.Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_MicronOpticsInc.Member" name="MicronOpticsInc.Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_MinimumRoyaltyPaymentsForPurchaseObligations" name="MinimumRoyaltyPaymentsForPurchaseObligations" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="luna_NatureOfOperationsPolicyTextBlock" name="NatureOfOperationsPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_NonEmployeeDirectorDeferredCompensationPlanMember" name="NonEmployeeDirectorDeferredCompensationPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_NumberofPurchaseCommitmentsExecuted" name="NumberofPurchaseCommitmentsExecuted" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_OptoelectronicComponentsAndSubassembliesMember" name="OptoelectronicComponentsAndSubassembliesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_OtherCountriesMember" name="OtherCountriesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_PaymentsToAcquireBusinessesGrossPaidAtClosing" name="PaymentsToAcquireBusinessesGrossPaidAtClosing" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="luna_PaymentsToAcquireBusinessesGrossPlacedInEscrow" name="PaymentsToAcquireBusinessesGrossPlacedInEscrow" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="luna_ProceedsFromStockOptionAndWarrantExercises" name="ProceedsFromStockOptionAndWarrantExercises" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_ProductAndLicensingSegmentMember" name="ProductAndLicensingSegmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_ProductsAndLicensingMember" name="ProductsAndLicensingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_ProductsAndServicesOpticalTestAndMeasurementSystemsMember" name="ProductsAndServicesOpticalTestAndMeasurementSystemsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_ProductsAndServicesOtherMember" name="ProductsAndServicesOtherMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_ProductsAndServicesTechnologyDevelopmentMember" name="ProductsAndServicesTechnologyDevelopmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_RestrictedStockAndRestrictedStockUnitsMember" name="RestrictedStockAndRestrictedStockUnitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_ScheduleOfDebtIssuanceCostsTableTextBlock" name="ScheduleOfDebtIssuanceCostsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" name="ScheduleOfPropertyPlantAndEquipmentUsefulLifeTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNumberOfVestingInstallments" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNumberOfVestingInstallments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsContractualTerm" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsContractualTerm" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimitBalance" name="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimitBalance" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="luna_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeRollForward" name="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeRollForward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperLimit" name="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperLimit" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="instant" />
  <xsd:element id="luna_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisedInPeriodExercisePriceRangeLowerRangeLimit" name="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisedInPeriodExercisePriceRangeLowerRangeLimit" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisedInPeriodExercisePriceRangeUpperRangeLimit" name="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisedInPeriodExercisePriceRangeUpperRangeLimit" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansForfeituresInPeriodExercisePriceRangeLowerRangeLimit" name="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansForfeituresInPeriodExercisePriceRangeLowerRangeLimit" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansForfeituresInPeriodExercisePriceRangeUpperRangeLimit" name="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansForfeituresInPeriodExercisePriceRangeUpperRangeLimit" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansGrantsInPeriodExercisePriceRangeLowerRangeLimit" name="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansGrantsInPeriodExercisePriceRangeLowerRangeLimit" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansGrantsInPeriodExercisePriceRangeUpperRangeLimit" name="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansGrantsInPeriodExercisePriceRangeUpperRangeLimit" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsAggregateIntrinsicValueForfeited" name="SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsAggregateIntrinsicValueForfeited" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="luna_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsNonvestedAggregateIntrinsicValueGranted" name="SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsNonvestedAggregateIntrinsicValueGranted" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="luna_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsissuableuponvesting" name="SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsissuableuponvesting" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant" />
  <xsd:element id="luna_SharebasedCompensationArrangementbySharebasedPaymentAwardRevenueandOperatingIncome" name="SharebasedCompensationArrangementbySharebasedPaymentAwardRevenueandOperatingIncome" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="luna_SignificantAccountingPoliciesLineItems" name="SignificantAccountingPoliciesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_SignificantAccountingPoliciesTable" name="SignificantAccountingPoliciesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_SignificantPurchaseCommitmentTimePeriod" name="SignificantPurchaseCommitmentTimePeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_SiliconValleyBankMember" name="SiliconValleyBankMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_TechnologyDevelopmentMember" name="TechnologyDevelopmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_TechnologyDevelopmentSegmentMember" name="TechnologyDevelopmentSegmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_TunableLasersMember" name="TunableLasersMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_UnitedStatesDirectCommercialSalesAndOtherMember" name="UnitedStatesDirectCommercialSalesAndOtherMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_UnitedStatesGovernmentMember" name="UnitedStatesGovernmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" name="WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="luna_WeightedAverageNumberOfShareOutstandingAbstract" name="WeightedAverageNumberOfShareOutstandingAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="luna_WorkingCapitalPayableCurrent" name="WorkingCapitalPayableCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
</xsd:schema>
