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简介：WefabricatephotoniccrystalslabmicrocavitiesembeddedwithGaAsquantumdotsbyelectronbeamlithographyanddropletepitaxy.ThePurcelleffectofexcitonemissionofthequantumdotsisconfirmedbythemicrophotoluminescencemeasurement.Theresonancewavelengths,widths,andpolarizationareconsistentwithnumericalsimulationresults.

简介：ThespinHalleffectoflight(SHEL)canbeobservedbythedarkstripresultingfromweakmeasurement.WefindthattheSHELofapartiallycoherentbeam(PCB)hasasimilarphenomenonaswell.However,thedarkstripintheSHELofaPCBcannotbeexplainedbyconsideringthebeamasanassemblanceofcoherentspeckles.Also,thedarkstripinaPCBisnotpurelydark.Byanalyzingtheautocorrelation,weshowthattheSHELofaPCBistheresultofoverlappingcoherentspeckles'SHEL.Wefurtherproveourconclusionbyadjustingconvergenceandincidentangles.Finally,wedevelopaqualitativetheorytoclarifytheSHELofaPCB.

简介：Alow-thresholdRamaneffectinakilowattytterbium-dopednarrowbandfiberamplifiersystemisreported.TheRamanStokeslightat1120nmisachievedwiththetotaloutputpowerofonly~400W,indicatingthattheRamanthresholdofthiskilowattcodirectionalpumpedcontinuouswavefiberamplifierismuchlowerthanthepredictedvalueestimatedbytheclassicformula.Tofigureoutthemechanismofthisphenomenon,simulationsbasedonthegeneralstimulatedRamanscattering(SRS)modelareanalyzedindicatingthatthekeyfactoristhecouplingbetweenfour-wavemixing(FWM)andSRS.Thesimulationresultsareingoodagreementwithourexperiments.

简介：ThreekindsofKH2PO4rawmaterialareusedtogrowdeuteratedpotassiumdihydrogenphosphate(DKDP)crystalsbytraditionalandrapidgrowthmethods,respectively.Thegrowthhabitdependenceonthepurityofrawmaterialisdescribedandanalyzed.Theopticalpropertiesincludingtransmissionspectraandlaser-induceddamagethresholdofthesecrystalsaremeasured.Itisfoundthatthegrowthmethodaffectstheopticalpropertiesofcrystalmoreobviouslythantherawmaterialwiththemasscontentofmainmetalionsbelow1ppm.Moreover,themorphologyofthecoreintheobserveddamagesitesindicatesthatanexplosionprocessprobablyoccursduringlaser-inducedbreakdown.

简介：Weproposeanovelsmall-anglemeasuringopticalmethodbasedontheastigmaticeffectoftwoorthogonallyplacedcylindricallenses.Accordingtotheone-to-onecorrespondencebetweenthelaserspotshapeandtheangle,theangleisdetermined.Wetheoreticallyanalyzethemeasuringrangeanddemonstratethatalongerdistancebetweentherotatingaxisandtheopticalaxisleadstoasmallermeasuringrange,butbettersensitivity.Also,anassociatedexperimentalsystemisestablishedandameasuringrangeof0.94mrad(cubicfitr=0.9993)aswellasagoodlinearrangeof0.37mrad(linearfitr=0.9994)witharesolutionof8μradisachieved.

简介：Cavity-coupledplasmonicstructureisdemonstratedtobeasimpleandeffectivetooltomanipulatelight,enhancethebiosensingfigureofmerit,andcontrolthepolarizationstate.InthisLetter,wedemonstratethetunabilityofthechiropticaleffectofcavity-coupledchiralstructure,i.e.,sandwichchiralmetamaterials(SCMs),inwhichradiationcouplingdominatestheinteractionbetweenparticles.TwotypesofSCMswhosebuildingblocksare3Dchiraland2Dchiral,respectively,arenumericallystudied.Distinctresponsesareobservedinthesetwomaterials.Thechiropticaleffectcanbeeffectivelymanipulatedandenhancedinthe2Dcase,whiletheSCMsconsistingof3Dchirallayerskeepthechiropticaleffectaconstant.Atheoreticalanalysisbasedonmatrixopticsisdevelopedtoexplainthecorrespondingphenomena,whichgivesareasonableagreementwithnumericalsimulations.

简介：Er3+-dopedheavymetalborosilicateglasseswerepreparedusingconventionalmeltingandquenchingmethod.Theemissionspectraof4Ⅰ13/2→4Ⅰ15/2transitionwereobserveduponexcitationat974nmandthelifetimeof4Ⅰ13/2levelofEr3+wasmeasured.Basedonthesedata,thefluorescencepropertiesofEr3+areinvestigatedontheemissionandgaincharacteristicsatthe1.5μmbands.Inparticular,theeffectofrelativeheavymetalcontentonfluorescencepropertiesisdiscussed.

简介：WhenfemtosecondlaserpulsesinterferewithchirpedfemtosecondlaserpulsesinAs2S3fiber,achirpedfibergratingisformed.Ananalyticalexpressionisgiventodescribethechirpedgrating,anditsBraggreflectivityiscalculated.BecauseofthehighphotosensitiveeffectofAs2S3material,thechirpedfibergratinghasawideBraggreflectivespectrumandhighreflectivitybychoosingproperparameters.Thisindicatesthatthechirpedfibergratingcanbeusedasastretcherinthefemtosecondchirpedpulseamplification(CPA)system.

简介：Theeffectsofvacuum-inducedcoherence(VIC)onthepropertiesoftheabsorptionandgainoftheprobefieldinanequispacedthree-levelladderatomicsystemareinvestigated.Itisfoundthatlasingwithoutinversion(LWI)isremarkablyenhancedduetotheeffectofVICinthecaseofthesmallincoherentpumprate.

简介：Inthiswork,wereportabroadbandterahertzwavemodulatorbasedonatop-gategraphenefieldeffecttransistorwithpolyimideasthegatedielectriconaPETsubstrate.ThetransmissionoftheterahertzwaveismodulatedbycontrollingtheFermilevelofgrapheneviathepolyimideasthetop-gatedielectricmaterialinsteadofthetraditionaldielectricmaterials.Itisfoundthattheterahertzmodulatorcanachieveamodulationdepthof~20.9%withasmalloperatinggatevoltageof3.5Vandalowinsertionlossof2.1dB.

简介：TheCa_2SiO_4:Dy~(3+)phosphorwassynthesizedbythehightemperaturesolid-statereactionmethodinair.TheemissionspectrumofCa_2SiO_4:Dy~(3+)phosphorshowsseveralbandsat486,575,and665nmunderthe365-nmexcitation.TheeffectsofLi~+,Na~+,andK~+ontheemissionspectrumofCa_2SiO_4:Dy~(3+)phosphorwerestudied,TheresultsshowthattheemissionspectrumintensityisgreatlyinfluencedbyLi~+,Na~+,andK~+.Thechargecompensationconcentrationcorrespondingtothemaximumemissionintensityisdifferentwithdifferentchargecompensations.

简介：Anoptimizeddesignoflaserrangefindingsystemusingtheself-mixingeffectinasingle-modevertical-cavitysurface-emittinglaser(VCSEL)isproposed.Inordertoimprovetherangingaccuracyandexpanddynamicmeasurementrange,weapplydifferencefrequencyanalogphase-lockedloop(PLL)insteadoffastFouriertransform(FFT)toprocesssignal,andchoosetheoptimumtriangularwavefrequencyfm=500Hzandsmallmodulationcurrent△Ip-p=0.28mAtomodulatesingle-modeVCSEL.Theexperimentresultsshowthat,withoutcontrollingthelaser'stemperature,therangingaccuracyisbetterthan2mmandthemeasurementdynamicrangeisaslargeas50-500mmwhenthesamplingtimeis0,1sandtheroomtemperatureis0-55℃.

简介：AseriesofAlx-(Alq3)1-xgranularfilmsispreparedonSiwaferwithnativeoxidelayerusingco-evaporationtechnique.Largelateralphotovoltaiceffect(LPE)isobserved,withanoptimalLPVsensitivityof75mV/mminx=0.35sample.ThedependenceofLPEontemperatureandAlcompositionisinvestigated,andthepossiblemechanismisdiscussed.

简介：Wehavestudiedafunction-lockstrategyforall-opticallogicgate(AOLG)utilizingthecross-polarizationmodulation(CPM)effectinasemiconductoropticalamplifier(SOA).Bymonitoringthepoweroflogiclight,thestrategyrealizedcontrollablemethodstocaptureORandNORfunctionsandswitchbetweenthem.Thestrategyhasbeensuccessfullyappliedinexperimentwith10-Gb/snot-return-to-zero(NRZ)signals,whichhasahighsuccess-rateabove95%andensuresthehighextinctionratioofresultlightabove11.4dB.Everystepinthestrategyhasdefinitenumericevaluation,whichprovidesthepotentialofautomaticimplementation.

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：Measurementsoftheexcitationpower-dependenceandtemperature-dependencephotoluminescence(PL)areperformedtoinvestigatetheemissionmechanismsofInGaN/GaNquantumwells(QWs)inlaserdiodestructures.ThePLspectralpeakisblueshiftedwithincreasingtemperatureoveracertaintemperaturerange.ItisfoundthattheblueshiftrangewaslargerwhenthePLexcitationpowerissmaller.ThisparticularbehaviorindicatesthatcarriersarethermallyactivatedfromlocalizedstatesandpartiallyscreenthepiezoelectricfieldpresentintheQWs.Thesmallblueshiftrangecorrespondstoaweakquantum-confinedStarkeffect(QCSE)andarelativelyhighinternalquantumefficiency(IQE)oftheQWs.

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