Low Level Pulsed Laser Radiometers

1 Page 1 INISTMeasurementServices: Calibrationserviceforlow-level nist pulsed-laserradiometersat1.06urn: 5 p f? ia, A , a r Publication Pulseenergyandpeakpower 25o-64 RodneyW.Leonhardt BOULDERLABS 1954 -2004 NationalInstituteofSt... Open at page → 2 Page 2 TechnicalPublications Periodical JournalofResearchoftheNationalInstituteofStandardsandTechnology—ReportsNISTresearch anddevelopment inmetrologyandrelatedfieldsofphysicalscience,engineering,appliedmathematics, statistics,... Open at page → 3 Page 3 NISTSpecialPublication250-64 NISTmeasurementservices: Calibrationserviceforlow-levelpulsed-laser radiometersat1.06pm: Pulseenergyandpeakpower RodneyW.Leonhardt Optoelectronics Division ElectronicsandElectricalEngineering... Open at page → 4 Page 4 Certaincommercial entities,equipment,ormaterialsmaybeidentifiedinthisdocument inordertodescribe anexperimentalprocedureorconceptadequately.Suchidentification isnotintendedtoimply recommendation orendorsementbytheNational... Open at page → 5 Page 5 Contents 1.INTRODUCTION 1 2.DESIGNREQUIREMENTSFORTHELOW-LEVELCALIBRATIONSYSTEM 2 2.1TheMeasurementProblem 2 2.2CalibrationSystem:PerformanceRequirements 2 2.3Transfer-Standard Definitions 3 3.DESCRIPTIONOFTHE1.06/umCALIB... Open at page → 6 Page 6 10.REFERENCES 27 AppendixA:SampleCalibrationReport 28 APPENDIXB.CalibrationProcedureOutline 35 APPENDIXC.ImpulseResponseMeasurementandBandwidthCorrectionCalculation 36 C.1Theneedforimpulseresponsemeasurementofpulsed-lase... Open at page → 7 Page 7 CalibrationServiceforLow-levelPulsed-LaserRadiometers at1.06/urn:PulseEnergyandPeakPower RodneyW.Leonhardt NationalInstituteofStandardsandTechnology Boulder,Colorado80305 IdescribethecalibrationserviceprovidedbytheNation... Open at page → 8 Page 8 2.DESIGNREQUIREMENTSFORTHELOW-LEVELCALIBRATIONSYSTEM 2.1TheMeasurementProblem Thedesignandcalibrationoftransferstandardssuitableforthemeasurementoflow-level,short- durationlaserpulsespresentsensitivityandspeedrequirement... Open at page → 9 Page 9 2.3Transfer-Standard Definitions Inordertominimizeconfusion,Iwilldefinethetypesoflasermeasurementstandardsreferredto inthisdocument.PrimarystandardsornationalstandardsareinstrumentsdevelopedatNISTto providemeasurementtra... Open at page → 10 Page 10 3.DESCRIPTIONOFTHE1.06/urnCALIBRATIONSYSTEM TheNISTmeasuringsystemgenerateslowlevelsofknownpeakpowerandenergytocalibratelaser radiometerresponse.Peakpowerorenergyinanyonebeamisdeterminedfromtheknownsplitting ratiosofapre... Open at page → 11 Page 11 3.1LaserSourceandShutter Thesourcefor1.06//mradiationisadiode-pumped, solid-stateNd:YAGlaser.Thelaser'scenter wavelengthis1.0643±0.0002//m,withspectralwidth(FWHM)of0.001yum.Also,thereisoutput inalasingmodecenteredat1.061... Open at page → 12 Page 12 3.4Multiple-Reflection Beamsplitter/Attenuator Wemakeextensiveuseofmultiple-reflectionwedgedbeamsplittersforattenuationincalibration systemsforlaserpowerorenergy.Thetheoryanduseofwedgedbeamsplittershavebeenwell documente... Open at page → 13 Page 13 Table3.1.Propertiesofthemultiple-reflection beamsplitter. Material:Si0 2 :fusedsilica IndexofRefraction: 1.4496±0.0001 [4] WedgeAngle:2.0±0.1 ° AngleofIncidence:-8.71±0.04° Wavelength:1.064±0.003/urn IndexofRefractionofA... Open at page → 14 Page 14 Table3.2.Fused-silicabeamsplitterratioscalculatedfromattributeslistedinTable3.1. beamA BeamB T"\_^a * arr*% RatioA/B RatioA/B RatioA/B Difference vertical horizontal mixed(50%)ofV&H (order,m=) (order,m=) polarization pol... Open at page → 15 Page 15 3.6Waveform-Measuring Instrument:Oscilloscope Thepulsed-energyandpeak-powerradiometersaresemiconductor-based andarecalibratedsuch thatthepeakvoltageoutputcorresponds tolaserpeakpowerorpulseenergy.Thevoltage measurement i... Open at page → 16 Page 16 Itshouldbenotedthattheintegratingamplifierintheradiometernotonlyintegratesthevoltage pulse,butalsodifferentiates,resultinginabipolarsignalfromtheradiometer(Figure6).Anydc offsetfromtheamplifierwillintroduceanerrorwhenmea... Open at page → 17 Page 17 5.CALIBRATIONOFLASERRADIOMETERSFORPEAK-POWERRESPONSE 5.1Peak-PowerCalibration Calibrationofthepeak-powerresponseoflaserradiometers isaccomplishedbycorrelatinga continuous-wave lasersignaltoapulsed-signalofequivalentmagni... Open at page → 18 Page 18 where: Kp p -peak-powercalibrationfactor(V/W) PV=averagepeakvoltagefromtheIUT(V) APP=averagepeakpower(W) BSR=beamsplitterratio(A/BratiofromTable3.2) Manyusersrequirethattheinputapertureoftheradiometerbeoverfilledwithalar... Open at page → 19 Page 19 5.2BandwidthofPeak-PowerTransferStandards Forapplicationsinlasermeasurementsuchaspulseenergyorcwpower,itisnotnecessarytoknow theimpulseresponseofthedetectionsystem.However,inordertomeasuretheshapeorpeakpower oflaserpulse... Open at page → 20 Page 20 6.2MeasurementofDetectorImpulseResponse TheimpulseresponsewaveformisobtainedbymeasuringtheresponseoftheAPDdetectortothe shortlaserpulseusingasimpleconfigurationasshowninFigure9.Adigitalsamplingoscilloscope (bandwidth: 1G... Open at page → 21 Page 21 Apeak-powerlaserradiometertypicallyincludesanexternalamplifierthatcanbeswitchedintothe circuittoprovideadditionalgainforthelowest-levelsignals.Eventhoughtheamplifierweuseis muchfasterthantheAPDdetectorandtheexpectedlaser... Open at page → 22 Page 22 7.MEASUREMENTUNCERTAINTY Thetotaluncertaintyassociatedwithaparticularmeasurementoflaser-pulseenergyorpeakpower iscomposedoftheindividualuncertaintiesofthecomponentsoftheentiresystem.Theactual magnitudeoftheerrorofeachunc... Open at page → 23 Page 23 7.1UncertaintyintheLaboratoryReferenceStandard Thereferencestandardusedinthelow-levelcalibrationsystemisitselfcalibratedagainstaNIST primarystandard.Individualcomponentsofuncertaintyofthistraceablecalibrationareincluded... Open at page → 24 Page 24 TheTypeAuncertaintycomponents,whichareevaluatedbystatisticalmethodsarethefollowing: (1)LaboratoryReference-Standard.TC-24 :Thestandarddeviationinthemeasurementrunsfor calibratingreference-standardTC-24withtheC-seriescalo... Open at page → 25 Page 25 dualbaselineevaluationsalsoprovidecorrectionforthermaldriftinTC-24,whichmayoccurduring thecalibrationperiod.Measurementsmadetocharacterize thepossibleleakageeffectafter subtractingthebaselineshowatypicaluncertaintyofless... Open at page → 26 Page 26 -300 -100 100 300 Time(ns) 500 700 -0.01 -150 50 150 Time(ns) 250 50 150 Time(ns) 350 Figure 11.Inputpulseshapesusedtotestinequivalence ofpulse-energyradiometers. 20 Open at page → 27 Page 27 7.3Pulsed-LaserRadiometerUncertaintyComponents CharacteristicsofthelaserradiometerorIUTalsocontributetotheoveralluncertaintyofits calibrationfactor.NormallyNISTwouldnotcharacterizespecificationsoftheinstrumenttobe calibr... Open at page → 28 Page 28 8.MEASUREMENTASSURANCE Historically,theexpandeduncertaintiesforlow-levellaserradiometershavebeenfairlyhigh,inthe 8to12%range.Thisisbecauseoftherelativelylongtraceablitychain,complexopticalalignment, andhighattenuationrat... Open at page → 29 Page 29 Table8.2CurrentcalibrationhistoryforTC-24. Date Range Primary Average Calibration Expanded standard power factor uncertainty (joules) (mW) (reading/J) (%) 4/24/95 10 C-series 10 1.640 0.90 »» 10 » 20 1.637 0.91 >» 10 » 3... Open at page → 30 Page 30 withspatialfiltering.Germaniumtrapdetectorswereusedtomeasuretheattenuationratios.The LOCRfacilityisahigh-accuracylaserpowerstandardoperatedbytheOptoelectronicsDivision[11]. At1.550yumtherewaslessthan1%differencebetweenth... Open at page → 31 Page 31 Table8.4APD-721peak-powercalibrationhistory. Date Amplifier gain (dB) Nominal pcaK-powcr Calibration factor [V/(W/cm 2 )] Number oiruns Standard deviation (%) Expanded uncertainty (%) 4-90 0 2 1.77X10 4 13 2.72 6.98 7-92... Open at page → 32 Page 32 Furtherconfirmationoftheconsistency isshowninTable8.6,thecalibrationhistoryforAPD-725. Thisunithasbeensentseveraltimestocustomersites,andhasbeenpartiallydisassembled,which mayaffecttheresponsivity. Itstillmaintainsastand... Open at page → 33 Page 33 Majorchangessuchasanewlaboratoryreferencestandard,ordifferentsoftwarecontrolofthe measurementsystem,willrequirethedocumentation tobeupdated. 10.REFERENCES [1]Saunders,A.A.;Rasmussen,A.L.;ASystemforMeasuringEnergyandPeakP... Open at page → 34 Page 34 AppendixA:SampleCalibrationReport U.S.DEPARTMENTOFCOMMERCE NATIONALINSTITUTEOFSTANDARDSANDTECHNOLOGY ELECTRONICSANDELECTRICALENGINEERINGLABORATORY Boulder,Colorado80305 REPORTOFCALIBRATION LOW-LEVELTRANSFERSTANDARD Natio... Open at page → 35 Page 35 LOW-LEVELTRANSFERSTANDARD APD900-01 NationalInstituteofStandardsandTechnology TableII.CalibrationSummary(smallbeamwithneutraldensityfilter) Amplifier Number Nominal Calibration Standard Expanded Gain& of Pulse Factor Dev... Open at page → 36 Page 36 LOW-LEVELTRANSFERSTANDARD APD900-01 NationalInstituteofStandardsandTechnology Diode Pumped Precision Attenuator Nd:YAG Laser Pulses n C Power Supply 1.08 \ cw ooo J yLowPowerBeam Laboratory Standard Oscilloscope oooo ooo... Open at page → 37 Page 37 LOW-LEVELTRANSFERSTANDARD APD900-01 NationalInstituteofStandardsandTechnology TableIV.CalibrationSummary -PulseEnergy(smallbeam;nofilters) Amplifier Number Nominal Calibration Standard Expanded Gain of Pulse Factor Devia... Open at page → 38 Page 38 LOW-LEVELTRANSFERSTANDARD APD900-01 NationalInstituteofStandardsandTechnology UncertaintyAssessment TheuncertaintyestimatesfortheNISTlaserenergyandpeak-powermeasurements areexpressedand combinedusingthefollowingguideline... Open at page → 39 Page 39 LOW-LEVELTRANSFERSTANDARD APD900-01 NationalInstituteofStandardsandTechnology TableVII.MeasurementUncertaintiesforPeak-PowerCalibration TYPEB TYPEA Source Source s r N U.1CVJUlVuXwLIWw 009% FlpctriralCalibration 010% Jv... Open at page → 40 Page 40 LOW-LEVELTRANSFERSTANDARD APD900-01 NationalInstituteofStandardsandTechnology TableVIII.MeasurementUncertaintiesforPulseEnergyCalibration TYPEB TYPEA Source Source s r N Inequivalence 0.09% ElectricalCalibration 0.10% 30... Open at page → 41 Page 41 APPENDIXB.CalibrationProcedureOutline 1.Ascertainthelaserradiometer'stypeandthedesiredcalibrationconditionsfromthecustomer. 2.Fromthelow-levelperformance specifications, calculatewhetherthemeasurementsystemcanbe configur... Open at page → 42 Page 42 APPENDIXC.ImpulseResponseMeasurementandBandwidthCorrectionCalculation C.lTheneedforimpulseresponsemeasurementofpulsed-laserdetectors Wecalibrateeachphotodiode-basedpeak-powertransferstandardusinglong-durationlaserpulsest... Open at page → 43 Page 43 C.2Bandwidthcorrectionprocedure 1.MeasuredetectorimpulseresponsewithconfigurationshowninFigureCI.Theimpulseresponse curvesareacquiredbyrecordingthevoltagesignalfromthedetectorinresponsetoveryshortlaser pulsesincidentonth... Open at page → 44 Page 44 APPENDIXD:SuitableTransferStandardsandShippingInstructions D.l.Transferstandardsthataresuitableforcalibration Thetransferstandardsthataresuitableforcalibrationinthelow-level 1.06pimsystemmustbeableto measurepulsedlaseren... Open at page → 47 Page 47 rhe NationalInstituteofStandardsandTechnologywasestablishedin1988byCongressto"assistindustryin thedevelopmentoftechnology ...neededtoimproveproductquality,tomodernizemanufacturingprocesses, toensureproductreliability ...... Open at page → 48 Page 48 0) | "2 o-o Oc OO) «o Q)CD t£ re "2 CL— 0)— QS .o "Ms 3Z 00 CO CO 1 m o CO o >*oo So -oO CO - Ois CQ LO CM O o CO 6* CD CO CD ft "TO CO> cd-a .£CL (A u_ 3o CQ *= 75^ COCOCO 1s 0=CD Oa. Open at page →