仪器资讯
AdvantagesofUsingPlasticHybridAsphericLenses
TECHSPECPlasticHybridAsphericLensesarelowcostopticalcomponentsthatlackbothsphericalandchromaticaberrations.Theseasphericlensesprovideopticaldesignerswithunique,singleelementsolutionsforachievingdiffraction-limitedfocusingperformanceathighnumericalapertureswithbroadbandlightsources.Theseasphericlensesconsistofadiffractivesurfacethathasbeenaddedtoamoldedasphericlens.Theasphericlenseliminatesallsphericalaberration,whilethediffractivesurfacehasaneteffectofintroducingnegativedispersionwhenproperlytunedtotherefractiveindexandwavelengthdesignofthelens,chromaticaberrationiseliminatedaswell.
SphericalandChromaticAberrations
Therearetwomajorformsofaxialopticalaberrationsinherentincommonopticallenses:sphericalaberrationandchromaticaberration.Sphericalaberrationisaninherentcharacteristicofanylenswhosesurfaceisasectionofasphere.Lightoriginatingfromthesameobjectpointcomestoafocusatslightlydifferentpoints(PandP’),dependingonwhethertherayspassthroughthecenterofthelensortheperiphery(Figure1).
Figure1:SphericalAberrationinaSinglePositiveLens
igure2.1:TransverseChromaticAberrationofaSinglePositiveLens
Figure2.2:LongitudinalChromaticAberrationofaSinglePositiveLens
Chromaticaberrationresultsfrommaterialdispersion.Becausedifferentcolorsoflightrefractbydifferentamounts,animagepointformedbylightofonecolordoesnotcoincidewiththecorrespondingimagepointformedbylightofadifferentcolor(Figures2.1and2.2).
ImportantEquations
Sphericalaberrationistypicallyeliminatedbysubstitutinganasphericalsurfaceforthemorecommonsphericalsurface.Thesurfaceprofile(sag)isgivenbyEquation1:
Where
Z=sagofsurfaceparalleltotheopticalaxis
s=radialdistancefromtheopticalaxis
C=curvature,inverseofradius
k=conicconstant
A4,A6,A8=4th,6th,8th…orderasphericterms
However,thisdoesnotcorrectchromaticaberration.Therefore,foramonochromaticlightsource,theasphericsurfacewillprovidediffractionlimitedfocusingatasinglewavelength,butwillsufferalargespotsizeoverabroaderwavelength.
Adiffractivesurfacewillcorrectthesphericalaberration,asshowninEquation2.
Where
Y=radialpositionfromcenteroflens(forinstance,if0isthecenterofthelens,12.5mmwillbetheedgeofa25mmdiameterlens,etc.)
nd=indexofrefractionofthematerialat587.6nm
StepHeight=λ/nd-1
λ=thewavelengthofinterest
Bycombiningthetwofeaturesontoasingleelement,acomponentthateliminatesbothchromaticandsphericalaberrationiscreated.ThatsurfaceisdescribedsimplyasthesumoftheZasphandZdiffcoefficients.
Fortipsonmode领diffractivesinZemaxandCodeV,visittheOpticsRealmblog.
CustomerBenefits
Opticaldesignersoftenneedtofocuslightatveryshortdistances,orcollectandcollimateasmuchlightaspossiblefromverydivergentlightsources.Basicopticalprinciplesdictatethatahighnumericalapertureopticallensisrequiredforeitherofthesescenarios.Ahighnumericalapertureopticallenswilltypicallyhaveafocallengthequaltoorshorterthantheclearapertureoftheopticalsystem,allowingthedesignertomaintainascompactofanopticaltrainaspossible.
Forexample,anopticaldesignerhasmultipleoptionsforachievingafocallengththatisequaltohisclearaperture(ascenarioknownasanF/1lens,oralenswithanumericalapertureof0.50).Thesimplestoptionistouseastandardplano-convexlens,availablefromanumberofdistributors.Spotdiagram,chromaticfocalshiftgraph,polychromaticdiffractionMTF,andtransverserayfanplotforthewavelengthrangeof486-656nmareprovidedfor#45-09725mmDiameterx25mmFLPCXlens.
PCXLens
Figure3.1:SpotDiagramfor#45-09725mmDia.x25mmFLPCXLens
Figure3.2:ChromaticFocalShiftGraphfor#45-09725mmDia.x25mmFLPCXLens
Figure3.3:PolychromaticDiffractionMTFGraphfor#45-09725mmDia.x25mmFLPCXLens
Figure3.4:TransverseRayFanPlotfor#45-09725mmDia.x25mmFLPCXLens
Forimprovedperformance,theopticaldesignercouldconsideranachromaticlensofthesameformfactor,forexample#65-55325mmDiameterx25mmFocalLengthAchromaticLens.Again,thesamecharacteristicsareshownoverthesamewavelengthrange.A74%decreaseinspotsizewitha73%decreaseinchromaticfocalshiftcanbeseen,yieldinganMTFof13lp/mmat40%contrast,asubstantialgainversustheaforementionedsingletlens.
Figure4.1:potDiagramfor#65-55325mmDia.x25mmFLAchromaticLens
Figure4.2:ChromaticFocalShiftGraphfor#65-55325mmDia.x25mmFLAchromaticLens
Figure4.3:PolychromaticDiffractionMTFGraphfor#65-55325mmDia.x25mmFLAchromaticLens
Figure4.4:TransverseRayFanPlotfor#65-55325mmDia.x25mmFLAchromaticLens
Formaximumperformance,theopticaldesigner首ldchooseaplastichybridasphericlens.Inthisscenario,theexactsameformfactorandwavelengthrangeareused,thistimewith#65-99225mmDiameterx25mmFLHybridAsphericLens.Asshown,thislensprovidesdiffractionlimitedfocusingperformance,yieldingtheoptimumperformanceforthedesigner.
PlasticHybridLens
Figure5.1:SpotDiagramfor#65-99225mmDia.x25mmFLHybridAsphericLens
Figure5.2:ChromaticFocalShiftGraphfor#65-99225mmDia.x25mmFLHybridAsphericLens
Figure5.3:PolychromaticDiffractionMTFGraphfor#65-99225mmDia.x25mmFLHybridAsphericLens
Figure5.4:TransverseRayFanPlotfor#65-99225mmDia.x25mmFLHybridAsphericLens
Comparingthespotdiagrams,chromaticfocalshiftgraphs,polychromaticdiffractionMTFs,andtransverserayfanplotsofaplano-convex(PCX)lens,achromaticlens,andhybridasphericlens,itiseasytoseetheadvantagesofusingplastichybridasphericlensesforachievingdiffraction-limitedfocusingperformanceathighnumericalapertureswithbroadbandlightsources.
SelectionGuide
EdmundOpticsTECHSPECPlasticAspheresandTECHSPECPlasticHybridAspheresfamiliesarebothmanufacturedutilizingZeonChemical’sZeonexE48Rmaterial.Zeonexmaterialsfeaturehightransparency,lowfluorescence,lowbirefrengence,lowwaterabsorption,andhighheatandchemicalresistance,makingitasuperiormaterialvs.othercommonlyavailableplastics.ZeonexisaCylcoOlefinPolymer(COP)material.
PlasticMaterialsSelectionGuide
Property
Glass
ZeonexE48R
PMMA
Polycarbonate
Polystyrene
Arton
Transmission
Excellent
Excellent
Excellent
Good
VeryGood
Excellent
LowRefractiveIndex
Excellent
Excellent
Excellent
Poor
Poor
Good
LowBirefringence
Excellent
Excellent
Excellent
Poor
Poor
Excellent
LowWaterAbsorption
Excellent
Excellent
Poor
Good
Excellent
Excellent
ImpactResistance
Poor
Good
Good
Excellent
Good
Excellent
Moldability
Fair
Excellent
Good
Excellent
Excellent
Good
HeatResistance
Excellent
Good
Poor
Good
Poor
VeryGood
CoatingAdhesion
Excellent
Good
Fair
Fair
Fair
Good
仪器网-专业分析仪器服务平台,实验室仪器设备交易网,仪器行业专业网络宣传媒体。
相关热词：
等离子清洗机,反应釜,旋转蒸发仪,高精度温湿度计,露点仪,高效液相色谱仪价格,霉菌试验箱,跌落试验台,离子色谱仪价格,噪声计,高压灭菌器,集菌仪,接地电阻测试仪型号,柱温箱,旋涡混合仪,电热套,场强仪万能材料试验机价格,洗瓶机,匀浆机,耐候试验箱,熔融指数仪,透射电子显微镜。
