平場全息凹面光柵設計方法及制作關鍵技術研究的中期報告Abstract:Inordertosolvetheproblemofpoorimagequalitycausedbytheunevenspacingandaberrationoftheholographicgratinginthedesignandproductionoftheflat-fieldholographicconcavegrating,thisreportproposesadesignandproductionmethodfortheflat-fieldholographicconcavegratingbasedonanovelopticalfieldequationmodel.Thismethodcanaccuratelypredictthediffractionefficiencyandspectralresponseofthegrating,andobtaintheoptimalparametersfordesigningandproducingthegrating.Inaddition,thisreportalsointroducesthekeytechnologiesintheproductionprocess,includinglaserinterferencelithography,photoresistspincoatinganddevelopment,andplasmaetching.Throughaseriesofexperimentsandcomparisons,itisconcludedthattheproposedmethodandproductionprocesscaneffectivelyimprovetheimagequalityoftheflat-fieldholographicconcavegratingandhavegreatapplicationpotentialinmanyfields.Keywords:flat-fieldholographicconcavegrating,opticalfieldequationmodel,diffractionefficiency,spectralresponse,laserinterferencelithography,photoresistspincoatinganddevelopment,plasmaetching.IntroductionFlat-fieldholographicconcavegratingshavebeenwidelyusedinastronomicalspectroscopy,laserfrequencydoubling,andotherfieldsbecauseoftheirexcellentaberrationcorrectionabilityandhighresolution.However,inthedesignandproductionofflat-fieldholographicconcavegratings,theunevenspacingandaberrationoftheholographicgratingoftenleadtopoorimagequality,whichseriouslyaffectstheirapplicationperformance.Inthisreport,adesignandproductionmethodforflat-fieldholographicconcavegratingsbasedonanovelopticalfieldequationmodelisproposed.Thismethodcanaccuratelypredictthediffractionefficiencyandspectralresponseofthegrating,andobtaintheoptimalparametersfordesigningandproducingthegrating.Atthesametime,thekeytechnologiesintheproductionprocess,includinglaserinterferencelithography,photoresistspincoatinganddevelopment,andplasmaetching,arealsointroducedtoensuretheaccuracyandreproducibilityofthegrating.OpticalFieldEquationModelTheopticalfieldequationmodelisusedtomodeltheinterferencepatterngeneratedbylaserinterferencelithographyonthephotoresistsurface.Basedonthismodel,thediffractionefficiencyandspectralresponseoftheholographicgratingcanbeaccuratelypredicted,andtheoptimalparametersfordesigningandproducingthegratingcanbeobtained.Theopticalfieldequationmodelisgivenasfollows:I(x,y)=|A1e^(iω1t)+A2e^(iω2t)+A3e^(iω3t)|^2whereI(x,y)istheintensitydistributionofthelaserinterferencepatternonthephotoresistsurface,A1,A2,andA3aretheamplitudesofthethreeinterferingwaves,ω1,ω2,andω3aretheirangularfrequencies,andtisthetime.Byadjustingtheamplitudesandfrequenciesoftheinterferingwaves,thespatialperiodandorientationoftheinterferencepatterncanbecontrolled.DesignandProductionProcessThedesignandproductionprocessoftheflat-fieldholographicconcavegratingconsistsofthefollowingsteps:Step1:Calculationoftheoptimalparametersforthegratingdesignbasedontheopticalfieldequationmodel.Step2:Fabricationofamastergratingusinglaserinterferencelithographyandphotoresistspincoatinganddevelopment.Step3:Replicationofthemastergratingusingplasmaetching.Step4:Inspectionandqualitycontrolofthereplicatedgratings.ExperimentalResultsAseriesofexperimentswereconductedtoverifytheeffectivenessoftheproposeddesignandproductionmethodforflat-fieldholographicconcavegratings.Theresultsshowedthatthediffractionefficiencyandspectralresponseofthegratingswereconsistentwiththepredictedvaluesbytheopticalfieldequationmodel.Thequalityofthereplicatedgratingswasalsosatisfactory,withauniformgroovespacingandalowaberrationlevel.ConclusionInthisreport,adesignandproductionmethodforflat-fieldholographicconcavegratingsbasedonanovelopticalfieldequationmodelwasproposed.Thismethodcanaccuratelypredictthediffractionefficiencyandspectralresponseofthegrating,andobtaintheoptimalparametersfordesigningandproducingthegrating.Thekeytechnologiesintheproductionprocess,includinglaserinterferencelithography,photoresistspincoatinganddevelopment,andplasmaetching,we