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16 个结果
  • 简介:SpecimensofPbTesinglefilmaredepositedonGesubstratesbyvacuumthermalevaporation.Duringthetemperaturerangeof80–300K,thetransmittanceofaPbTefilmwithin2–15μmismeasuredevery20KbythePerkinElmerFouriertransforminfraredspectroscopycryogenictestingsystem.Then,therelationshipbetweentherefractiveindexandwavelengthwithin7–12μmatdifferenttemperaturesisreceivedbythefullspectruminversionmethodfitting.ItcanbeseenthattherelationshipconformstotheCauchyformula,whichcanbefitted.Then,therelationshipbetweentherefractiveindexofthePbTefilmandthetemperature/wavelengthcanbeexpressedasn(λ,T)=5.82840-0.00304T+4.61458×10~(-6)T~2+8.00280∕λ~2+0.21544∕λ~4,whichisobtainedbythefittingmethodbasedontheCauchyformula.Finally,thedesignedvalueobtainedbytheformulaandthemeasuredspectrumarecomparedtoverifytheaccuracyoftheformula.

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  • 简介:Alightpurplishredsapphireisheattreatedinanairtightcrucible.Thesamplechangeslittleincolorafterreceivingheattreatmentat1100°C,butturnstolightblueandblueafterbeingtreatedat1200°Cand1300°C,respectively.Beforeheating,theUV-VISabsorptionspectraofthesamplearedominatedbythe551nmbroadabsorptionbandcontributedbythed-electrontransition~4A_2→~4T_2ofCr~(3+).Afterheating,theUV-VISabsorptionspectraaredominatedbythe563nmbroadabsorptionbandcontributedbytheintervalencechargetransferofFe~(2+)-Ti~(4+).ThexrayphotoelectronspectroscopytestrevealsthattheFe~(2+)andTi~(4+)ioncontentsincreasewithincreasingtemperature.ThesapphirechangingfromlightpurplishredtoblueintheheatingprocessisowingtothefactthattheFe~(2+)andTi~(4+)contentsgrowandtheintervalencechargetransferofFe~(2+)-Ti~(4+)selectivelyabsorbsUV-VISlight.

  • 标签: 低温热处理 蓝宝石 紫红色 紫外-可见吸收光谱 X射线光电子能谱 加热过程
  • 简介:Asimplifiedringcavityforachievingaunidirectionalroomtemperaturemulti-wavelengtherbium-dopedfiberringlaserwithoutopticalisolatorisdemonstrated.ThefiberringcavityisbuiltinsuchawaythattheopticalfieldspropagatingintwodirectionssufferdifferentlossescausedbyonesampledfiberBragggrating.Furthermore,simultaneousmulti-wavelengthlasingwith0.8-nmintervalsisdemonstratedwithsinusoidalphasemodulationjustbeforethesampledfiberBragggratingtopreventsingle-wavelengthlasingandunstablewavelengthoscillation.

  • 标签: 单向室温多波长铒掺杂光纤环激光器 光纤布拉格光栅 光学隔离器 光纤环形腔 输出功率
  • 简介:一个简单波长无关的规模因素模型为靠近环的干涉仪纤维被建立眼的回转仪(IFOG)和一个方法被建议为空格申请在高效IFOG把规模因素作为容忍的放射和温度马厩。一半波浪电压(在不同波长和温度的多功能旋转罗盘薄片的V)被测量,调节的人的放射无关的固有的参数被选出并且发现与温度并且稍微成正比波长依赖者。试验性的IFOG被开发,规模因素分别地在不同温度并且在Co60照耀下面被测量。不到10ppm规模因素不稳定性在40以内被完成??

  • 标签: 干涉型光纤陀螺 温度稳定 标度因数 性能 波长依赖性 辐射测量
  • 简介:Anewwavelengthbeamcombiningtechniqueforahigh-powerlaserdiodebarbyusingatemperaturegradientheatsinkhasbeenproposed.Thethermalcontrollingprincipleofthetemperatureheatsinkhasbeendiscussed.Ithasbeenprovedbyexperimentthatthelineartemperaturedistribution,whichgenerateslinearwavelengthspreadoftheoutputbeamsfromaLDbar,canbeobtainedbyintroducingatemperaturegradientheatsinkandtheoutputbeamscanbefocusedintoarelativesmallspotbyusingtheCzerny-Turnerbeamshapingsystem.

  • 标签: 大功率激光二极管 固体激光器 温度分布
  • 简介:AnovelfiberBragggrating(FBG)withtwotransmissiondipsin1310-and1550-nmregionsisproposedandinscribedbyaninfraredfemtosecondlaser.Formedbymulti-photonionization,thistypeofgratingcanwithstandtemperatureashighas800℃whichmakesitsuitableforharshenvironmentsensing.Inaddition,thetemperatureandstrainaffectthesetwodipsindifferentways,whichenablessimultaneousstrainandtemperaturesensing.Thefabrication,spectrumcharacterization,andtemperatureperformanceofthisgratingareintroduced.

  • 标签: 光纤光栅 同时测量 应变 光刻 飞秒 双波长
  • 简介:Influenceoftemperatureonmeasurementofsurfaceplasmonresonance(SPR)sensorwasinvestigated.SampleswithvariousconcentrationsofNaClweretestedatdifferenttemperatures.Itwasshownthatiftheaffectionoftemperaturecouldbeneglected,measurementprecisionofsaltsolutionwas0.028wt.-%.Butmeasurementerrorofsalinityca,usedbytemperaturewas0.53wt.-%inaveragewhenthetemperaturedriftwas1℃.Toreducetheerror,adouble-cellSPRsensorwithsaltsolutionanddistilledwaterflowingrespectivelyandatthesametemperaturewasimplemented.更多还原

  • 标签: 误差测量 传感器 测量精度 表面等离子谐振 盐溶液
  • 简介:ThesensitivityofDopplerwindlidarisanimportantparameterwhichaffectstheperformanceofDopplerwindlidar.Aerosolscatteringratio,atmospherictemperature,andwindspeedobviouslyaffectthemea-surementofDopplerwindlidarwithiodinefilter.Wediscussabouttherelationshipbetweenthemea-surementsensitivityandtheaboveatmosphericparameters.Thenumericalrelationshipbetweenthemisgiventhroughthetheoreticalsimulationandcalculation.

  • 标签: 气溶胶 灵敏性 温度 散射率
  • 简介:A1.3-μmwavelengthvertical-mesaridgewaveguidemulitple-quantum-well(MQW)distributedfeedback(DFB)laserwithhighdirectlymodulatedbandwidthandwideoperationtemperaturerangeisreported.Withtheoptimizationofthestrained-layerMQWsintheactiveregion,thesurroundinggraded-indexseparated-confinement-heterostructurewaveguidelayers,togetherwiththeoptimizationofthedetuningandcouplingcoefficientoftheDFBgrating,highdirectlymodulationbandwidthof16GHzatroomtemperatureandwideworkingtemperaturerangefrom-40to85℃areobtained.Themeantimetofailure(MTTF)isestimatedtobeover2×10~6h.Thedeviceissuitableaslightsourceofhigh-bit-rateopticaltransmitterswithsmallsizeandreducedcost.

  • 标签: DFB激光器 工作温度范围 脊波导 平均无故障时间 非制冷 分布式反馈
  • 简介:AFourieranalysisappliedtotheMach–Zehnderinterferometer(MZI)transmissionspectrumforsimultaneousrefractiveindex(RI)andtemperaturemeasurementsisproposedandexperimentallydemonstratedinthisLetter.InthefastFouriertransform(FFT)spectrumoftheMZItransmissionspectrum,severalfrequencycomponentsaregenerallyobserved,whichmeansthatthetransmissionspectrumoftheMZIisformedbythesuperpositionofsomedual-modeinterference(DMI)spectra,andeachfrequencycomponentrepresentsdifferentcore-claddinginterferences.WecanselectsomedominantfrequencycomponentsintheFFTspectrumoftheMZItransmissionspectrumtotaketheinverseFFT(IFFT).Then,thecorrespondingDMIpatternscanbeobtained.DuetotheshiftofthewavelengthoftheseDMIspectrawithchangesintheenvironmentalparameters,wecanusethecoefficientmatrixoftheseDMIspectraformulti-parametersensing.InthisLetter,twoDMIpatternsareseparatedfromtheresultanttransmissionspectrumoftheMZI.AstheRIandtemperaturechange,theshiftsofthetwoDMIpatternswithrespecttotheRIandtemperaturewillbeobserved.ThesensitivitiesoftheRIandtemperatureare-137.1806nm∕RIU(RIunit)and0.0860nm∕°C,and-22.9955nm∕RIUand0.0610nm∕°CforthetwoDMIs.Accordingly,itcanbeusedtosimultaneouslymeasureRIandtemperaturechanges.Theapproachcaneliminatetheinfluenceofmultipleinterferencesandimprovetheaccuracyofthesensor.

  • 标签: 温度测量 干涉仪 折射率 全光纤 DMIS 快速傅里叶变换
  • 简介:Biasofring-laser-gyroscope(RLG)changeswithtemperatureinanonlinearway.ThisisanimportantrestrainingfactorforimprovingtheaccuracyofRLG.Consideringthelimitationsofleast-squaresregressionandneuralnetwork,weproposeanewmethodoftemperaturecompensationofRLGbiasbuildingfunctionregressionmodelusingleast-squaressupportvectormachine(LS-SVM).StaticanddynamictemperatureexperimentsofRLGbiasarecarriedouttovalidatetheeffectivenessoftheproposedmethod.Moreover,thetraditionalleast-squaresregressionmethodiscomparedwiththeLS-SVM-basedmethod.TheresultsshowthemaximumerrorofRLGbiasdropsbyalmosttwoordersofmagnitudeafterstatictemperaturecompensation,whilebiasstabilityofRLGimprovesbyoneorderofmagnitudeafterdynamictemperaturecompensation.Thus,theproposedmethodreducestheinfluenceoftemperaturevariationonthebiasoftheRLGeffectivelyandimprovestheaccuracyofthegyroscopeconsiderably.

  • 标签: 最小二乘支持向量机 环形激光陀螺仪 温度补偿 偏置 建模 最小二乘回归
  • 简介:AseriesofAlx-(Alq3)1-xgranularfilmsispreparedonSiwaferwithnativeoxidelayerusingco-evaporationtechnique.Largelateralphotovoltaiceffect(LPE)isobserved,withanoptimalLPVsensitivityof75mV/mminx=0.35sample.ThedependenceofLPEontemperatureandAlcompositionisinvestigated,andthepossiblemechanismisdiscussed.

  • 标签: 成分依赖性 横向光电效应 温度 硅结构 金属 光生伏打效应
  • 简介:TransientthermalimpedanceofGaN-basedhigh-powerwhitelightemittingdiodes(LEDs)iscreatedusingathermaltransienttester.Anelectro-thermalsimulationshowsthatLEDjunctiontemperature(JT)risestoaverylowdegreeunderlowdutycyclepulsedcurrent.AtthesameJT,emissionpeaksareequivalentatpulsedandcontinuouscurrents.Moreover,thediferenceinpeakwavelengthwhenaLEDisdrivenbypulsedandcontinuouscurrentsinitiallydecreasesthenincreaseswithincreasingpulsewidth.Thus,selectinganappropriatepulsewidthdecreaseserrorsinJTmeasurement.

  • 标签: 白光LED 结温测量 大功率 GaN 白光发光二极管 瞬态热阻抗
  • 简介:Measurementsoftheexcitationpower-dependenceandtemperature-dependencephotoluminescence(PL)areperformedtoinvestigatetheemissionmechanismsofInGaN/GaNquantumwells(QWs)inlaserdiodestructures.ThePLspectralpeakisblueshiftedwithincreasingtemperatureoveracertaintemperaturerange.ItisfoundthattheblueshiftrangewaslargerwhenthePLexcitationpowerissmaller.ThisparticularbehaviorindicatesthatcarriersarethermallyactivatedfromlocalizedstatesandpartiallyscreenthepiezoelectricfieldpresentintheQWs.Thesmallblueshiftrangecorrespondstoaweakquantum-confinedStarkeffect(QCSE)andarelativelyhighinternalquantumefficiency(IQE)oftheQWs.

  • 标签: 斯塔克效应 量子限制 温度诱导 光致发光 GaN 管结构