简介:Toimprovethefrequencystabilizationoflaserdiodeinthelaserfrequencyscannedinterferometricmetrology,amodifiedmethodisproposedbyusingafiberringresonator.Thetheoreticalanalysisofthismodifiedmethodisperformed.Moreover,thePound-Drever-Hall(PDH)techniqueisemployedtoobtainthefrequencydiscriminationcurveofafiberringresonator,whosefinesseis1260andline-widthis270kHz.Thesimulatedresultsshowthatthecurvehasasteepslopeneartheresonantfrequency,whichprovesthesensitivityofthissystemtothefrequencydeviation,sothemodifiedmethodhasgreatpotentialforthefrequencystabilizationofalaserdiode.
简介:Spurredonbytheinventionofthebluelight-emittingdiode(LED)aquarterofacenturyago,theLEDindustryhasadvanceddramaticallyandhasrevolutionizedthesignaling/signage,mobileandflatpaneldisplay,andmorerecently,generallightingmarkets.Indeed,LEDsnowout-surpassinperformanceallconventional(e.g.,incandescent,fluorescent,high-intensitydischarge)lightsourcesingeneralilluminationapplications.Thequestionarises:whatmoreistobedone?ThuscomesthethesisforthisspecialissueonLEDsandapplications.Fromthecontributedarticles,welearnthatLEDtechnologycontinuestoevolveandtransformitselfnotonlywithintheexistingapplicationsbutisalsopositioningforbrandnewapplicationstocome,bothofwhicharehighlightedhere.
简介:Superluminescencediode(SLD)moduleswithwidespectrumcharacteristicsarerequiredinfibergyroscopes.A1.3μmbutterflypackagedsuperluminescencediodewiththespectrumwidthover30nmisreportedandrecentadvancesinprocessofSLDisdescribedinthepaper.TheSLDmoduleshavebeenappliedtofibergyroscopes.
简介:Laserdriversareanenablingfactortoinertialconfinementfusion,becauselaserdiodesmustbeusedinsteadofflashlamps.Wediscussthelimitationsoflaserdiodearraysandshowwhatstepstheindustryistaking.Thepumppowerrequirementsoflarge-scaleprojectssuchasLIFEorHiPERarewithinreachofsemiconductorlaserdiodeassemblies.Pulsedlightoutputpowersperlaserbarshavebeenaround300Wperbar,asintheJenoptik940nmbarspreviouslyusedforpumpingtheYb:YAGslabsintheDiPOLEproject.Byredesigningthesemiconductorlaserstructures500Wperbarisnowcommerciallyavailablefor808,880and940nmpumpwavelengths.Theconstructionofoneinertialfusionpowerplantwillrequireanamountofsemiconductorlaserchipsinexcessofthecurrentannualproductionbytwoordersofmagnitude.Thisaddstotheengineeringtaskofimprovingthedevicecharacteristicsachallengetoproductioncapacity.Whiletheindustrybenefitsfromtherecentboostinsolid-statelightingthatactsasatechnologydriver,cooperationbetweenmanufacturerswillbeimperative,andtothisendweproposestandardizationefforts.
简介:Thispaperreviewsthedifferentchallengesthatareencounteredinthedeliveryofhighpowerlasersasdriversforfusionenergy.Wewillfocusondiode-pumpedsolid-statelasersandwewillhighlightsomeofthemainrecentachievementswhenusingytterbium,cryogeniccoolingandceramicgainmedia.Apartfromsomeexistingfusionfacilitiesandsomemilitaryapplicationsofdiode-pumpedsolid-statelasers,wewillshowthatdiode-pumpedsolid-statelasersarescalabletoinertialfusionenergy(IFE)’sfacilitylevelandthattheall-fiberlaserschemeisverypromising.
简介:Thewavelengthtuningragesofagratingexternal-cavitylaserdiode(ECLD)havebeenstudiedbytheequivalentavitymethod.Themaximumtuningrange(MTR)andthecontinuoustundingrange(CTR),whicharerelatedtothemaximumandtheminimumthresholdcarrierdensities,arededucedfromthethresholdcondition.WedefinearatiooftheCTRtotheMRT.ThisratioisonlydeterminedbythereflectivitiesoftheexternalandinternalfacetsoftheECLD.TheanalysisshowsthatthereisanappropriatecombinationoftheexternalandinternalcavityreflectivitestoobtainagivenCTRinthedesignofanECLD.
简介:InGaN-basedlight-emittingdiode(LED)asforthereplacementofconventionalfluorescentlightingsourcestillneedsagreatefforttoimprovethelight-extractingefficiencyaswellasinternalquantumefficiencyofLEDs.Surfaceplasmontechnologyhasrecentlyattractedconsiderableinterest,becausethespontaneousemissionrateandthelightextractionefficiencyofalight-emittingdevicecanbesimultaneouslyenhancedthroughthecouplingbetweenanInGaNquantumwellandsurfaceplasmons.Thesurfaceplasmon-emittercouplingtechniquewouldleadtohighbrightnessmultichipwhiteLEDsthatofferrealisticalternativestoconventionalfluorescentlightsources.Inthisarticle,thepossibleenhancementmechanismofsurfaceplasmonisdiscussed,andthenrecentdevelopmentsofsurface-plasmon-enhancedlight-emittingdiodeareintroduced.
简介:Adiodelaserarray(DLA)positionedinanexternalcavitycanreceivetheradiationsemittedfromitsneighboringelements(C1)andthatofitself(S)afterbeingreflectedattheDLAfacetaswellasfromtheexternalmirror(C0).Consideringthefactthat|C0/S|shouldbelargerthanunityiftheexternalcavityiseffective,and|C1/S|shouldbelargerthanunityifthephaselockingmaybeestablishedintheexternalcavity.Therequirementsonthereflectionatthefacetofthediodelaserarrayhavebeenspecifiedintermsofthecavitylengthandreflectioncoefficientoftheexternalmirror.
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简介:Anewcollimationsystem,theheteroaxialdoublehalf-ellipticalcylinderlens(HDHECL),isproposedbasedontheraytracingmethod,andthecollimationperformanceoftheHDHECLisdiscussedandcomparedwithconventionallenses.ThesimulationresultssuggestthattherefractiveindexoftheHDHECLcanbelargerthan2,thecollimationeffectisimprovedwiththeincreaseoftherefractiveindexinacertainrange,andthedivergenceangleinthefast-axisdirectioncanbecompressedtolessthan0.01mradtheoretically.Theseresultsareofsignificanceintheoryandpractice.
简介:Inapracticalcouplingsystem,acylindricalmicrolensisusedtocollimatetheemissionofahighpowerlaserdiode(LD)inthedimensionperpendiculartothejunctionplane.Usingpassivealignment,theLDisplacedinthefocusofthecylindricalmicrolensgenerally,regardlessoftheperformanceofthemultimodeopticalfiberandtheLD.Inthispaper,amorecompleteanalysisisarrivedatbyray-tracingtechnique,bywhichtheangleθoftherayafterrefractioniscomputedasafunctionoftheangleθooftheraybeforerefraction.ThefocusofthecylindricalmicrolensisnotalwaystheoptimalpositionoftheLD.Infact,inordertoachieveahighercouplingefficiency,theoptimaldistancefromtheLDtothecylindricalmicrolensisdependentonnotonlytheradiusRandtheindexofrefractionnofthecylindricalmicrolens,butalsothedivergenceangleoftheLDinthedimensionperpendiculartothejunctionplaneandthenumericalaperture(NA)ofthemultimodeopticalfiber.Theresultsofthisdiscussionareingoodagreementwithexperimentalresults.
简介:AIMTo检验light-emitting-diode(带)导致的网膜的neuronal房间损坏和它的波长驱动的病原的mechanisms.METHODSSprague-Dawley老鼠暴露于蓝色LEDs(460nm),绿LEDs(530nm),和红LEDs(620nm)。染色的网膜电图描述术(尔格)(H&E),Hematoxylin和曙红,传播电子显微镜学(TEM),标记的终端deoxynucleotidyltransferasedUTP刻痕结束(TUNEL),和染色的immunohistochemical(IHC),西方的弄污(WB)并且superoxide阴离子的察觉(O2桰獯桰牯汹瑡潩???歁???????????椠浭湵景畬牯獥散据??啓呌??
简介:Anewwavelengthbeamcombiningtechniqueforahigh-powerlaserdiodebarbyusingatemperaturegradientheatsinkhasbeenproposed.Thethermalcontrollingprincipleofthetemperatureheatsinkhasbeendiscussed.Ithasbeenprovedbyexperimentthatthelineartemperaturedistribution,whichgenerateslinearwavelengthspreadoftheoutputbeamsfromaLDbar,canbeobtainedbyintroducingatemperaturegradientheatsinkandtheoutputbeamscanbefocusedintoarelativesmallspotbyusingtheCzerny-Turnerbeamshapingsystem.
简介:Wereport,forthefirsttimetoourknowledge,anon-chipmode-lockedlaserdiode(OCMLLD)thatemploysmultimodeinterferencereflectorstoeliminatetheneedoffacetmirrorstoformthecavity.TheresultisanOCMLLDthatdoesnotrequirecleavedfacetstooperate,enablingustolocatethisOCMLLDatanylocationwithinthephotonicchip.ThisOCMLLDprovidesasimplesourceofopticalpulsesthatcanbeinsertedwithinaphotonicintegratedcircuitchipforsubsequentphotonicsignalprocessingoperationswithinthechip(modulation,opticalfiltering,pulseratemultiplication,andsoon).Thedevicewasdesignedusingstandardizedbuildingblocksofagenericactive/passiveInPtechnologyplatform,fabricatedinamulti-projectwaferrun,andachievedmode-lockingoperationatitsfundamentalfrequency,giventheuncertaintyatthedesignstepoftheopticallengthofthesemirrors,criticaltoachievecollidingpulsemode-lockedoperation.
简介:Weproposeanultra-widebandopticaldiodedevicebasedontwo-dimensionalsquare-latticephotoniccrystals.Forthedevice,theoddmodeiscompletelytransmittedinonedirectionandconvertedtothefundamentalevenmode,butcompletelyreflectedintheotherdirection.Theoperationbandwidthofthedeviceispreservedwithinaratherwiderangeoffrequencies,whichisover6.5%ofthecentralfrequency.Adirectionalcouplerand90°bendareutilizedasthecompositefunctiondevicewithmodefilterandmodeconverter.Itispossiblethatthephotoniccrystaldevicecanhelptoconstructon-chipopticallogicaldevicesandbenefitgreatlytotheopticalsystemswithmultiplespatialmodes.更多还原
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.