简介:Theeffectofλ/2SiO2overcoatonthelaserdamagecharacteristicsofHfO2/SiO2high-reflector(HR)coatingsisinvestigatedwith1-on-1andN-on-1laserdamagetestmethods.Thelaserdamagesurfaceof1-on-1isanalyzedbyastepanalyzer.ThesurfacemorphologiesshowthatlaserdamagemakesthecoatingdamagedareaprotrudentandroughforHRcoatingwithoutλ/2silicaovercoat,butconcaveandsmoothforHRcoatingwithλ/2silicaovercoat.Theresultof10-on-1multi-pulseirradiationonthesamepointofthecoatingshowsthatthereisanenergydensitystageonthedamagecurve.Ifthelaserenergydensityiswithintherangeofthestage,HfO2/SiO2HRcoatingswithλ/2silicaovercoatwillnotbedamagedmorethan2timesformulti-shots,andthesurfacedamagesareveryslightsothatthereisnoimpactonthecoatingperformance.Anotherinterestingresultisthattheenergydensitystageextendsfromthedamagethresholdtothepointofabout3timesofthreshold,whichissimilartotheeffectofthelaserconditiononcoating.
简介:与传统宽波段成像系统相比,多光谱成像系统在性能表征、测试方法等方面有较大不同,而相关研究较为欠缺。因此,需要重点研究多光谱成像系统的综合性能评估方法。解决了目标光谱反射率等效控制、宽波段光谱维度的带内细分和标准靶标辐亮度调节等关键技术,设计了基于AOTF的多光谱成像系统二维鉴别率阈值测试平台及测试方法。在理论分析基础上,实际搭建了基于AOTF的可见光多光谱成像系统,叙述了系统标定方法和测试步骤,并基于所述方法在实验室条件下完成了系统空间分辨率、目标光谱反射率与对比度阈值的三维曲面测试实验。测试结果标明,所提出的方法可较好地反映不同谱段响应特性的差异,实现对多光谱成像系统的性能表征。基于该方法,可综合评估系统光谱分辨率、空间分辨率、灵敏度、对比度等性能指标,从而为多光谱成像系统性能的定量表征提供技术支持。
简介:为了精确地检测非旋转对称的非球面面形质量,将衍射补偿元件计算全息图(CGH)应用到非球面透射式检测光学系统中。利用计算全息图(CGH)可以生成任意形状的波前这一特点,对由三次面形和双曲面叠加而成的集成式波前编码器件进行检测,详细地给出了从检测系统的设计、计算全息图数学模型的建立,到CGH的制作和制作误差分析的过程。以口径33.84mm的波前编码器件为例,检测系统的模拟残余波像差的峰谷值是0.0373λ,均方根为0.0063λ。利用激光直写技术,加工制作了口径为56mm的计算全息板,计算全息图的制作误差为0.086λ,验证了计算全息图在检测自由曲面中的可行性。
简介:Thenonlinearswitchingcharacteristicsoffusedfiberdirectionalcouplerswerestudiedexperimentally.Byusingfemtosecondlaserpulseswithpulsewidthof100fsandwavelengthofabout1550nmfromasystemofTi:sapphirelaserandopticalparametricamplifier(OPA),thenonlinearswitchingpropertiesofanullcoupleranda100%couplerweremeasured.Theexperimentalresultswerecoincidentwiththesimulationsbasedonnonlinearpropagationequationsinfiberbyusingsuper-modetheory.Nonlinearlossinfiberwasalsomeasuredtogettheinjectedpoweratthecoupler.Afterdeductingthenonlinearlossandinputefficiency,thenonlinearswitchingcriticalpeakpowersfora100%andanullfusedcouplerswerecalculatedtobe9410and9440W,respectively.ThenonlinearlossparameterPNinanexpressionofαNL=αP/PNwasobtainedtobePN=0.23W.
简介:Thepotentialenergycurves(PECs)ofBOmolecule,includingΣ+andΠsymmetrieswithdoubletspinmultiplicities,areobtainedemployingmulti-referenceconfigurationinteraction(MRCI)methodandDunning'scorrelationconsistentbasissets.Theanalyticalpotentialenergyfunctions(APEFs)arefittedusingtheMurrell-Sorbie(MS)functionandtheleastsquaremethod.BasedonthePECs,thespectroscopicconstantsofthestateshavebeendeterminedandcomparedwiththetheoreticalandexperimentalresultsavailabletoaffirmtheaccuracyandliabilityofthecalculations.Theroot-mean-square(RMS)errorsbetweenthefittedresultsandtheabinitiovaluesaretoolittleincomparisonwiththechemicalaccuracy(349.755cm-1).ItisshownthatthepresentAPEFsareaccurateandcandisplaytheinteractionbetweentheatomswell.ThepresentAPEFscanbeusedtoconstructmorecomplicatedAPEFordosomedynamicinvestigations.
简介:Usingamicrowavegenerator,chlorinedilutedbyheliumwasdissociatedtochlorineatomsthatsubse-quentlyreactedwithhydrogenazidetoproducetheexcitedstatesofNCl(a1△).Meanwhile,moleculariodinewithcarriergasofheliumreactedwithatomicchlorinetoproduceatomiciodinewhichthenwaspumpedtoexcitedstateofI(2P1/2)byanenergytransferreactionfromNCl(a1△).Inthispaper,thechangesofNCl(a1△)andNCl(bi∑)emissionintensityispresentedwhenI2/HeisintroducedintothestreamofCl/Cl2/He/HN3/NCl(a1△)/NCl(b1∑).ThedependencesofatomiciodineI(2P1/2)onflowratesofgaseswerealsoinvestigated.TheoptimumparametersforI(2P1/2)productionaregiven.
简介:FourkindsofY2O3stabilizedZrO2(YSZ)thinfilmswithdifferentY2O3contents(from0to12mol%)aredepositedonBK7glasssubstratesbyelectron-beamevaporationmethod.TheeffectsofdifferentY2O3dopantcontentsonresidualstress,structure,andopticalpropertiesofZrO2thinfilmsareinvestigated.TheresultsshowthatresidualstressinYSZthinfilmsvariesfromtensiletocompressivewiththeincreaseofY2O3molarcontent.TheadditionofY2O3isbeneficialtothecrystallizationofYSZthinfilmandtransformationfromamorphoustohightemperaturephase,andtherefractiveindexdecreaseswiththeincreaseofY2O3molarcontent.Moreover,thevariationsofresidualstressandtheshiftsofrefractiveindexcorrespondtotheevolutionofstructuresinducedbytheadditionofY2O3.
简介:利用单色平行光照射玻璃微珠,入射光在玻璃微珠内经过一次或多次内反射后出射光在最小偏向角会形成彩虹条纹。基于几何光学理论,根据最小偏向角的大小计算玻璃微珠的折射率。为了实现其快速测量,采用参数递推公式计算Otsu法的最佳阈值,并用改进的Otsu法对彩虹图进行了有效的阈值分割。提出了一种能快速有效判断彩虹条纹边缘的方法,并用该方法自动测量了彩虹条纹最外环边缘半径,从而实现了最小偏向角的快速计算。此外,对玻璃微珠折射率测量过程中的不确定度进行了计算,对不同型号的玻璃微珠,折射率的不确定度在10-4数量级,验证了上述方法的正确性。
简介:Ag-MgF2cermetfilmswithdifferentAgfractionswerepreparedbyvacuumevaporation.Themicrostruc-tureofthefilmswasexaminedbyRamanscatteringtechnique.Thesurface-enhancedRamanspectrumforMgF2moleculesinthecermetfilmstronglysuggeststheexistenceofAgnanoparticlesdispersedinMgF2matrix.TheintensitiesoftheRamanspectraofAg-MgF2cermetfilmsincreasewithAgfraction.TheenhancementofRamanscatteringdisappearswhenAgcontentreacheswt.20%.TheanalyseswiththetransmissionelectronmicroscopyshowedthatAg-MgF2cermetfilmsaremainlycomposedofamor-phousMgF2matrixwithembeddedfaced-center-cubicAgnanoparticles.Itsuggeststhatthepercolationthresholdshouldbearoundwt.20%ofAgcontent.
简介:基于流场界面厚度(Interfacial—Fluid—Thickness,IFT)理论,建立了高折射率梯度门限模型来研究气动光学窗口光传输畸变。首先在光学窗口折射率梯度场基础上,提出高折射率梯度门限,忽略绝对值低于该门限的折射率梯度值,重构折射率场,并对其气动光学传输效应进行仿真。结果表明,当58.37%的梯度值被忽略时,得到的重构折射率场与原折射率场仿真光程差(OPD)最大相对误差不超过1.5%,验证了气动光学窗口高折射率梯度区域是产生光传输畸变的主要原因,也证实了该门限模型对气动光学窗口光传输效应进行仿真的可行性,对气动光学失真的机理、预测及校正有一定的指导意义。