简介:Aperiodicallypoledlithiumniobate(PPLN)opticalparametricgenerator(OPG)pumpedbyalaserdiode(LD)-pumpedQ-switchedTm,Ho:GdVO_4laseroperatedat2.048μmwithpumppulseof25nsandrepetitionrateof10kHzisreported.Acontinuoustunablemiddle-infrared(mid-IR)spectrumof3.88-4.34μmisobtainedbychangingthecrystaltemperaturefrom50to124°C.Whentheincidentpumppoweris3W,thetotalOPGoutputpoweris95mW,correspondingtoopticalconversionefficiencyof3.2%.
简介:EnhancementoflightextractioninaGaInNlight-emittingdiode(LED)employinganomni-directionalreflector(ODR)consistingofGaN,SnO_2nanorodandanAglayerwaspresented.TheODRcomprisesatransparent,quarterwavelayerofSnO_2nanorodcladedbysilverandservesasanohmiccontacttop-typeGaN.TransparentSnO_2solswereobtainedbysol-gelmethodfromSnCl_2·2H_2O,andSnO_2thinfilmswerepreparedbydip-coatingtechnique.TheaveragesizeofthesphericalSnO_2particlesobtainedis200nm.TherefractiveindexofthenanorodSnO_2filmlayeris2.01.TheGaInNLEDswithGaN/SnO_2/AgODRshowalowerforwardvoltage.ThiswasattributedtotheenhancedreflectivityoftheODRthatemploysthenanorodSnO_2filmlayer.ExperimentalresultsshowthatODR-LEDshaveloweropticallossesandhigherextractionefficiencyascomparedtoconventionalLEDswithNi/AucontactsandconventionalLEDsemployingadistributedBraggreflector(DBR).
简介:AhighlyTm-dopedleadgermanateglassfiberisdevelopedusingtherod-in-tubemethod.The~2μmlaserbeamqualityofthefiberis~1.5.Theleadgermanatecompositefiberjumpersarehomemadeforallthefiberlaserinvestigations.Whencoreispumpedbya1590nmYb/Erfiberlaser,amaximumlaseroutputof313mWisachievedata670mWpumppower,andthecorrespondingslopeefficiencyis~52.8%.Moreover,byusinga2cmlongleadgermanatefiberasthegainmedium,a33mW1942nmTmlaserisalsodemonstrated.
简介:Anultra-broadbandandfabrication-tolerantsiliconpolarizationrotatorsplitterisproposedinthisLetter.Benefittingfromthebroadbandandlow-losscharacteristicsofthebi-leveltaperandcounter-taperedcoupler,thedesigneddevicehasasimulatedinsertionlossandcrosstalkoflessthan0.2and-15dBinthewavebandfrom1290to1610nm.Thesecharacteristicsmakeitvaluableinapplicationswithlargebandwidthrequirements,suchasfull-gridCoarsewavelengthdivisionmultiplexer(CWDM)anddiplexer/triplexerfiber-to-the-homesystems.Thefabricationtoleranceofthedesignisalsoanalyzed,showingthatthedeviceperformanceisquitestablewithnormalmanufacturingerrorsinsiliconphotonicsfoundries.
简介:AseriesofAlx-(Alq3)1-xgranularfilmsispreparedonSiwaferwithnativeoxidelayerusingco-evaporationtechnique.Largelateralphotovoltaiceffect(LPE)isobserved,withanoptimalLPVsensitivityof75mV/mminx=0.35sample.ThedependenceofLPEontemperatureandAlcompositionisinvestigated,andthepossiblemechanismisdiscussed.
简介:Wereportonthecontinuous-wave(CW)andpassiveQ-switchingperformanceofaminiatureYb:Y3Ga5O12crystallaserendpumpedbya935-nmdiodelaser.AmaximumCWoutputpowerof12.03Wisproducedwithanoptical-to-opticalefficiencyof54.4%,whiletheslopeefficiencyis63%.InthepassivelyQ-switchedoperationachievedwithaCr4+:YAGsaturableabsorber,anaverageoutputpowerof2.12Wat1025.2nmisgeneratedwithaslopeefficiencyof46%atapulserepetitionrateof5.0kHz.Thepulse’senergy,duration,andpeakpowerare424μJ,2.3ns,and184.3kW,respectively.
简介:SiO_2thinfilmscontainingSi_(1-x)Ge_xquantumdots(QDs)arepreparedbyionimplantationandannealingtreatment.Thephotoluminescence(PL)andmicrostructuralpropertiesofthinfilmsareinvestigated.ThesamplesexhibitstrongPLinthewavelengthrangeof400—470nmandrelativelyweakPLpeaksat730and780nmatroomtemperature.Blueshiftisfoundforthe400-nmPLpeak,andtheintensityincreasesinitiallyandthendecreaseswiththeincreaseofGe-dopingdose.Weproposethatthe400—470nmPLbandoriginatesfrommultipleluminescencecenters,andthe730-and780-nmPLpeaksareascribedtotheSi=OandGeOluminescencecenters.
简介:Weexperimentallydemonstratea4-Gb/sradio-over-fiber(RoF)systemwith40-kmfiberand2-mwirelessdistancedownstreamat100-GHzcarrier.Tothebestofourknowledge,thisisforthefirsttimeinChinatorealizeopticalwirelesslinkat100GHz.Inthisletter,simpleintensitymodulatorwithdirectdetector(IM-DD)modulationisemployedandopticalpowerpenaltyafter40-kmsinglemodefiber(SMF)-28and2-mairlinkis3.2dBwithbit-error-rate(BER)at1×109.
简介:Adiode-end-pumpedelectro-optic(EO)Q-switchedNd:YVO4laseroperatingatrepetitionrateof10kpps(pulsespersecond)wasreported.AblockofLa3Ga5SiO14(LGS)singlecrystalwasusedasaQ-switchandthedriverwasametaloxidesemiconductorfieldeffecttransistor(MOS-FET)pulserofhighrepetitionrateandhighvoltage.Atcontinuouswave(CW)operation,theslopeefficiencyofthelaserwas46%,andmaximumoptical-to-opticalefficiencywas38.5%.Usinganoutputcouplerwithtransmissionof70%,a10-kppsQ-switchedpulsetrainwith0.4-mJmonopulseenergyand8.2-nspulsewidthwasachieved,theopticalconversionefficiencywasaround15%,andthebeamqualityM2factorwaslessthan1.2.
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。