简介：Afeasiblemethodofcombiningtheconceptoffluorescencehalf-lifeandthepowerdependentphoto-bleachingrateforcharacterizingthepracticalphotostabilityoffluorescentproteins(FPs)wasintroduced.Furthermore,byusingafluorescentphotostabilitystandard,arelativecomparisonofthephotostabiltyofFPsfromdifferentresearchgroupswasproposed,whichwouldbeofgreatbenefitfordevelopingnovelFPswithoptimizedemissionwavelength,betterbrightness,andimprovedphotostability.Weusedrho-damineBasanexampletoverifythismethodandevaluatethepracticalphotostabilityofafar-redFP,mKate-S158C.Experimentalresultsindicatedgoodpotentialofthismethodforfurtherstudy.

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

简介：Amethodofdetectingdry,icyandwetroadsurfaceconditionsbasedonscanningdetectionofsinglewavelengthbackwardpowerisproposedinthisletter.Thedetectorisusedtoreceivethebackwardscatteredpowerwhichchangeswiththeincidenceangle.Therelationshipbetweenbackwardpowerandincidenceangleisusedtofindouttheeffectiveanglerangeanddistinguishmethod.Experimentandsimulationshowthatitisfeasibletoclassifythesethreeconditionswithinincidenceangleof5.3degree.

简介：Wedemonstrateadiode-pumpTm3+t-dopedall-fiberlaseroperatingat1908nmbasedonamasteroscillatorpoweramplifier（MOPA）configuration.Inourwork,152Woflaseroutputpowerisgeneratedbyatotalincidentpumppowerof434Wat790nm,correspondingtothetotalopticalefficiencyof35%.Thelaserwavelengthis1908.29nm.Tothebestofourknowledge,itisthehighestoutputpowerreachedaround1908nmwithsuchanarrowlinewidthof0.18nmbasedonaMOPAconfiguration.

简介：AnovelschemeofopticalpowerequalizationbasedonFabry-Perotsemiconductoropticalamplifier(FP-SOA)isproposed.BecauseofthegaincharacteristicofFP-SOA,real-timecontrollingmechanismaccordingtoinputopticalpowerisabortedinthescheme.Thesimulationsshowthat10-dBpulsepeakpowervariationcanbeclampedinlessthan1dB.Theinfluencesofinjectingcurrent,pulseperiods,andpulsewidtharediscussed.

简介：Inapracticalcouplingsystem,acylindricalmicrolensisusedtocollimatetheemissionofahighpowerlaserdiode(LD)inthedimensionperpendiculartothejunctionplane.Usingpassivealignment,theLDisplacedinthefocusofthecylindricalmicrolensgenerally,regardlessoftheperformanceofthemultimodeopticalfiberandtheLD.Inthispaper,amorecompleteanalysisisarrivedatbyray-tracingtechnique,bywhichtheangleθoftherayafterrefractioniscomputedasafunctionoftheangleθooftheraybeforerefraction.ThefocusofthecylindricalmicrolensisnotalwaystheoptimalpositionoftheLD.Infact,inordertoachieveahighercouplingefficiency,theoptimaldistancefromtheLDtothecylindricalmicrolensisdependentonnotonlytheradiusRandtheindexofrefractionnofthecylindricalmicrolens,butalsothedivergenceangleoftheLDinthedimensionperpendiculartothejunctionplaneandthenumericalaperture(NA)ofthemultimodeopticalfiber.Theresultsofthisdiscussionareingoodagreementwithexperimentalresults.

简介：

简介：Anewwavelengthbeamcombiningtechniqueforahigh-powerlaserdiodebarbyusingatemperaturegradientheatsinkhasbeenproposed.Thethermalcontrollingprincipleofthetemperatureheatsinkhasbeendiscussed.Ithasbeenprovedbyexperimentthatthelineartemperaturedistribution,whichgenerateslinearwavelengthspreadoftheoutputbeamsfromaLDbar,canbeobtainedbyintroducingatemperaturegradientheatsinkandtheoutputbeamscanbefocusedintoarelativesmallspotbyusingtheCzerny-Turnerbeamshapingsystem.

简介：Anovelnonlinearopticalloopmirror(NOLM)withanonreciprocalphaseshiftbias(NPSB),calledpowerequalizationNOLM(PE-NOLM),isproposedforreducingthepowerfluctuationofpulsetrains.NPSBprovidespartofthenonreciprocalphasedifferencesothattherequiredinputpowerisreduced,andnonsymmetricalcouplingratioofcouplercanadjustthetransmissioncurvetoimprovetheequalizationrange.IthasbeenshowntheoreticallythatcomparedwithearlierPE-NOLM,about1.6dBofequalizationpowerreductionandabout2.2dBofequalizationrangeenhancementcouldbeachieved.Experimentshavedemonstratedthattheoutputpowerfluctuationisreducedtolessthan0.4dB,whiletherequiredinputpeakpowerrangeis4.5dBm(15.6-20.1dBm).

简介：Ahigh-repetitionratemasteroscillatorpoweramplifierpumpedwithlaserdiodes(LDs)isreported.Aninjectionseedingsingle-frequencyelectro-opticalQ-switchedNd:YAGlaserisusedasanoscillator,andaconductivelycooledNd:YAGzigzagslabwithabounce-pumpedarchitectureisutilizedasapoweramplifier.Pulseenergiesofover800mJat1064nmand400mJat532nm,correspondingtoaveragepowersof200and100W,respectively,areachievedwitha12.6-nspulsewidthat250Hz.Outputfrequencyfluctuationsandsingle-frequencyoperationarefurthermonitored.Experimentalresultsrevealthattheproposedsystem,whichfeaturesasingle-passamplifiedconfiguration,isapromisingdesignforspace-basedapplications.

简介：Withthedevelopmentofhighpowerultrafastlaserpassivelymode-lockedbyasemiconductorsaturableabsorbermirror(SESAM),thedamagethresholdanddegenerationmechanismoftheSESAMbecomemoreandmoreimportant.OnewaytoreducethemaximumelectricfieldinsidetheactivepartoftheSESAMistheuseofadielectriccoatingonthetopofthesemiconductorstructure.WithFresnelformula,opticaltransfermatrix,andopticalthinfilmtheory,theelectricfielddistributionandreflectancespectrumcanbesimulated.WeintroducethedesignprinciplesofSESAMincludingthedependenceofreflectancespec-trumondielectricfunctionofabsorber,andinvestigatethedependencesoftheelectricfielddistribution,modulationdepth,reflectancespectrum,andtherelativevalueofincidentlightpoweratthetopquantumwellofSESAMonthenumberofSiO_2/Ta_2O_5layers.

简介：Ahigh-powerpulsedpumpmethodisproposedtoobtainahigh-energyoutputwithanimprovedsignalto-noiseratio(SNR)duringpulseamplification.Basedonnumericalanalysis,theytterbium-dopedfiberamplifiersarecomparedunderdifferentpumpingconditions.Atthesamesignalgain,theoutputusingthehigh-powerpulsedpumpshowsgreatSNRimprovementandreducedoutputsignaldistortion,comparedwithacontinuous-wavepumpandalow-powerpulsedpump.Byadjustingthepumpparameters,theamplifiercanachievetheoptimaloutputSNRwithoutsacrificingthesignalgain.Webelievethatthehigh-powerpulsedpumpschemeisverysuitableforthehigh-energynanosecondpulseamplification,whichhasahighSNRrequirement.

简介：Anoptimalpowerdistributionanalysisforanall-opticalsamplingorthagonalfrequencydivisionmultiplexing(OFDM)schemewithmultiplemodulationformatsincludingdiferentialphaseshiftkeyed(DPSK),diferentialquadraturephaseshiftkeyed(DQPSK),andnon-return-to-zero(NRZ)isproposed.Thenoisetolerancesofdifferentmodulationformatsareanalyzed,andtheoptimalinputpowerratiobetweenphaseandintensitymodulationformatsforthebestoverallreceivingperformanceisinvestigatedunderunchangedtotalinputpower.Moreover,thisschemecanseamlesslycoexistwiththetraditionalWDMchannel.

简介：Thenumericalstudyontheperformanceoflarge-mode-area(LMA)fiberscoiledontoaspoolinhighpoweramplifieriscarriedoutasthebend-induceddistortionoffibermodesseverelyaffectstheoutputcharacteristicsofamplifiersystems.Thevariationsforhigh-ordermodebenddistortionwithdifferentorientationsrelativetotheplaneofthefiberbendareobservedandshown.Concerningthepracticalapplications,abend-resistantLMAfiberwiththemodearealargerthan1000μm2andexcellenthighordermodesuppressionisdesignedcompletelybyoptimizingtherefractiveindex(RI)anddopantprofile.TheresultsindicatethatahybridprofileofRIanddopantisthebestchoiceforLMAfiberwithcoiling.

简介：Atunableslowlightof2.5-Gb/spseudo-randombinarysequencesignalusinga1550-nmvertical-cavitysurface-emittinglaser(VCSEL)isexperimentallydemonstrated.Theinfluencesofthebiascurrentandthegainsaturationontheslowlightareinvestigated.Withbiascurrentincreasing,tunableopticalgroupdelayupto98psisobtainedatroomtemperature.Demonstrationofthetimedelaybetween16and24psbysignalintensitychangeisreported.Underanappropriatebiascurrent,bytuningtheinputsignaltotrackthepeakgainwavelengthoftheVCSEL,slowlightofapowerpenaltyaslowas1dBisachieved.Withsuchalowpowerpenalty,theVCSELhasagreatpotentialapplicationasacompactopticalbuffer.

简介：Thispaperreportsahighpower,all-solid-state,quasi-continuous-wavetunableTi:sapphirelasersystempumpedbylaserdiode(LD)pumpedfrequency-doubledNd:YAGlaser.Themaximumtunedoutputpowerof4.2W(797nm)andtunedaveragepowerof3.7WwereachievedwhenfixingtheTi:sapphirebroadbandoutputpowerat5.0Wandapplying750-850nmbroadbandcoatedmirror.

简介：Anall-solid-statequasi-continuous-wavedispersioncavitytunableTi:sapphirelaserpumpedbyalaserdiodepumpedfrequency-doubledNd:YAGlaserisreported.Usingadenseflintglassprismasthedispersionelement,atuningrangefrom730to880nmwiththelinewidthof3nmandthepulsewidthof17.2nswasobtained.Themaximumoutput,powerofthislasersystemwas5.6Wat786.3nmcorrespondingtoanoptical-to-opticalconversionefficiencyof25.5%underthepumppowerof22W.

简介：一个新奇的黑磷(BP)答案可饱和的吸收器(SA)被liquid-phase-exfoliated方法制作并且成功地使用了为消极地切换Q(QS)Nd:YVO4激光。与传统的稳固的SA相比，BP答案SA拥有更优秀的光透明性和更高的损坏抵抗。最短的脉搏持续时间和最高平均的产量力量被测量分别地是119ns和1.23W。就我们的知识而言，他们俩是在QS之中的最好的结果固态有基于BP的吸收器的激光到目前为止。重复率在533.2～722kHz的范围。结果显示BP答案SA的潜在的申请进高力量固态脉搏激光。

简介：TransientthermalimpedanceofGaN-basedhigh-powerwhitelightemittingdiodes(LEDs)iscreatedusingathermaltransienttester.Anelectro-thermalsimulationshowsthatLEDjunctiontemperature(JT)risestoaverylowdegreeunderlowdutycyclepulsedcurrent.AtthesameJT,emissionpeaksareequivalentatpulsedandcontinuouscurrents.Moreover,thediferenceinpeakwavelengthwhenaLEDisdrivenbypulsedandcontinuouscurrentsinitiallydecreasesthenincreaseswithincreasingpulsewidth.Thus,selectinganappropriatepulsewidthdecreaseserrorsinJTmeasurement.

简介：ThestimulatedBrillouinscattering(SBS)thresholdaffectedbyrepetitionrateandpulsedurationinasinglefrequencynanosecondpulsedfiberamplifierisstudied.TheexperimentalresultsdemonstratethattheSBSthresholdcanbeimprovedeitherbyreducingtherepetitionrateorbynarrowingthepulseduration;however,theaveragepowermaybelimitedinsomecases.Otherwise,twoevaluationmethodsfortheSBSthresholdinthefiberamplifierarecomparedanddiscussed,aimingtoobtainamoreaccuratedescriptionfortheSBSthresholdinoursingle-frequencyamplifiersystem.