简介：Vertical-cavitysurface-emittinglasers(VCSELs)aretheidealopticalsourcesfordatacommunicationandsensing.Indatacommunication,largedataratescombinedwithexcellentenergyefficiencyandtemperaturestabilityhavebeenachievedbasedonadvanceddevicedesignandmodulationformats.VCSELsarealsopromisingsourcesforphotonicintegratedcircuitsduetotheirsmallfootprintandlowpowerconsumption.Also,VCSELsarecommonlyusedforawidevarietyofapplicationsintheconsumerelectronicsmarket.Theseapplicationsrangefromlasermicetothree-dimensional(3D)sensingandimaging,includingvarious3Dmovementdetections,suchasgesturerecognitionorfacerecognition.NovelVCSELtypeswillincludemetastructures,exhibitingadditionaluniqueproperties,oflargestimportancefornext-generationdatacommunication,sensing,andphotonicintegratedcircuits.

简介：Theeffectofmesasizeonthethermalcharacteristicsofetchedmesavertical-cavitysurfaceemittinglasers(VCSELs)isstudied.ThenumericalresultsshowthatthemesasizeofthetopmirrorstronglyinfluencesthetemperaturedistributioninsidetheetchedmesaVCSEL.Underacertaindrivingvoltage,withdecreasingmesasize,thelocationofthemaximaltemperaturemovestowardsthep-contactmetal,thetemperatureinthecoreregionoftheactivelayerrisesgreatly,andthethermalcharacteristicsoftheetchedmesaVCSELswilldeteriorate.

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

简介：Opticalcouplingbehaviorandassociatedeffectsintwo-dimensionalimplant-definedcoherentlycoupledverticalcavitysurface-emittinglaser(VCSEL)arraysarestudiedviabothexperimentsandtheoreticalcalculations.Experimentsshowthatopticalcouplingbetweenarrayelementscanenhancethearray’soutputpower.Additionally,opticalcouplingvialeakyopticalfieldscanprovideextraopticalgainforthearrayelements,whichcanthenreducethethresholdsoftheseelements.Elementscanevenbepumpedwithoutcurrentinjectiontoemitlightbyreceivingastrongleakyopticalfieldfromotherarrayelements.Opticalcouplingcanalsocauseunusualphenomena:thecentralelementsinlarge-areacoherentlycoupledVCSELarraysthatlasepriortotheouterelementswhenthearraysarebiased,ortheaverageinjectioncurrentrequiredforeachelementtolase,whichismuchlowerthanthethresholdforasingleVCSEL.Theoreticalcalculationsareperformedtoexplaintheexperimentalresults.

简介：InGaN-basedlight-emittingdiode(LED)asforthereplacementofconventionalfluorescentlightingsourcestillneedsagreatefforttoimprovethelight-extractingefficiencyaswellasinternalquantumefficiencyofLEDs.Surfaceplasmontechnologyhasrecentlyattractedconsiderableinterest,becausethespontaneousemissionrateandthelightextractionefficiencyofalight-emittingdevicecanbesimultaneouslyenhancedthroughthecouplingbetweenanInGaNquantumwellandsurfaceplasmons.Thesurfaceplasmon-emittercouplingtechniquewouldleadtohighbrightnessmultichipwhiteLEDsthatofferrealisticalternativestoconventionalfluorescentlightsources.Inthisarticle,thepossibleenhancementmechanismofsurfaceplasmonisdiscussed,andthenrecentdevelopmentsofsurface-plasmon-enhancedlight-emittingdiodeareintroduced.

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简介：Anintracavityfrequency-doubledverticalexternalcavitysurfaceemittinglaser(VECSEL)withgreenlightisdemonstrated.ThefundamentalfrequencylasercavityconsistsofadistributedBraggreflector(DBR)ofthegainchipandanexternalmirror.A12-mWfrequency-doubledoutputhasbeenreachedat540nmwithanonlinearcrystalLBOwhenthefundamentalfrequencyoutputis44mWat1080nm.Thefrequencydoublingefficiencyisabout30%.

简介：Amethodbasedonthetheoryoftransfermatrixtodesigntheintegratedmicrolensforthecollimationofvertical-cavitysurfaceemittinglaser(VCSEL)arrayispresented.Theintegratedmicrolensesfabricatedonthesubstratedirectlyandonacertainpolymermaterialwhichisonthesubstrateareconsidered.Therelationshipsbetweentheradiusofcurvature,beamwaistandthedivergenceangleaftercollimationareobtainedwiththehelpofZEMAX.Theresultsshowthatthedeviceswiththedivergenceangleof15°(1/e2)andbeamwaistof2μmcanbeimprovedtothosewiththedivergenceanglelowerthan1°,andthedeviceswithbeamwaistof10μmcanbeimprovedtothosewiththedivergenceanglelowerthan3°,whichisagoodreferenceformanufacturinghigh-powerdeviceswithsmalldivergenceangle.Theconclusionsincludingincreasingthethicknessesofboththesubstrateandpolymermaterialandreducingthediameterofoxidizedlayeraredrawn,whichwillbeanimportantguidanceforexperimentresearch.

简介：ＰＡＲＡＭＥＴＲＩＣＳＵＲＦＡＣＥ／ＳＵＲＦＡＣＥＩＮＴＥＲＳＥＣＴＩＯＮＺｅｎｇＸｉａｎｇｌｉｎ；ＷａｎｇＱｉｆｕ；ＺｈｏｕＪｉ；ＹｕＪｕｎＰＡＲＡＭＥＴＲＩＣＳＵＲＦＡＣＥ／ＳＵＲＦＡＣＥＩＮＴＥＲＳＥＣＴＩＯＮ￥ＺｅｎｇＸｉａｎｇｌｉｎ；Ｗａｎ...

简介：Wehavefabricatedatop-emittingorganiclight-emittingdeviceonsiliconsubstratewithhighyellowluminancebasedon5,6,11,12-tetraphenylnaphthacenesub-monolayer.Itconsistsofathinlayerofhighlyconductivesilverasthesemitransparentcathodeandsurfaced-modifiedAgastheanode.Thedeviceturnsonat3Vwiththeluminanceof8.4cd/m^2.Themaximumcurrentefficiencyis1.3cd/Aat6Vandtheluminancereaches14790cd/m^2at14V.Theperformanceofthedeviceisexcellentintop-emittingorganiclight-emittingdevicesaccordingtoourknowledge.

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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：Theinvertedbottom-emittingorganiclight-emittingdevices（IBOLEDs）wereprepared,withthestructureofITO/A1（xnm）/LiF（1nm）/Bphen（40nm）/CBP：Girl（14%）：R-4b（2%）（10nm）/BCP（3nm）/CBP：Glrl（14%）：R-4b（2%）（20nm）/TCTA（10nm）/NPB（40nm）/MoO3（40nm）/A1（100rim）,wherethethicknessofelectroninjectionlayerA1（x）are0nm,2nm,3nm,4nmand5nm,respectively.Inthispaper,theelectroninjectionconditionandluminancepropertiesofinverteddeviceswereinvestigatedbychangingthethicknessofA1layerinAFLiFcompoundthinfilm.ItturnsoutthattheintroductionofA1layercanimproveelectroninjectionofthedevicesdramatically.Furthermore,thedeviceexertslowerdrivingvoltageandhighercurrentefficiencywhenthethicknessofelectroninjectionA1layeris3nm.Forexample,thecurrentefficiencyofthedevicewith3-urn-thickA1layerreaches19.75cd·A^-1whendrivingvoltageis7V,whichis1.24,1.17and17.03timeslargerthanthoseofthedeviceswith2nm,4nmand5nmA1layer,respectively.Thedevicepropertyreachesuptothelevelofcorrespondingconventionaldevice.Inaddition,allin-verteddeviceswithelectroninjectionA1layershowsuperiorstabilityofcolorcoordinateduetotheadoptionofco-evaporationemittinglayerandBCPspacer-layer,andthecolorcoordinateoftheinverteddevicewith3-nm-thickAIlayeronlychangesfrom（0.5806,0.4056）to（0.5328,0.4363）whendrivingvoltageincreasesfrom6Vto10V.

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简介：Inthisarticlewedefineasurfacefiniteelementmethod(SFEM)forthenumericalsolutionofparabolicpartialdifferentialequationsonhypersurfacesFinR~(n+1).ThekeyideaisbasedontheapproximationofFΓbyapolyhedralsurfaceΓ_hconsistingofaunionofsimplices(trianglesforn=2,intervalsforn=1)withverticesonF.AfiniteelementspaceoffunctionsisthendefinedbytakingthecontinuousfunctionsonΓ_hwhicharelinearaffineoneachsimplexofthepolygonalsurface.WeusesurfacegradientstodefineweakformsofellipticoperatorsandnaturallygenerateweakformulationsofellipticandparabolicequationsonΓ.Ourfiniteelementmethodisappliedtoweakformsoftheequations.Thecomputationofthemassandelementstiffnessmatricesaresimpleandstraightforward.Wegiveanexampleoferrorboundsinthecaseofsemi-discretizationinspaceforafourthorderlinearproblem.Numericalexperimentsaredescribedforseverallinearandnonlinearpartialdifferentialequations.Inparticularthepowerofthemethodisdemonstratedbyemployingit,tosolvehighlynonlinearsecondandfourthorderproblemssuchassurfaceAllen-CahnandCahn-Hilliardequationsandsurfacelevelsetequationsforgeodesicmeancuryatureflow.

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简介：Inthispaper,amethodtoconstructasurfacewithpointinterpolationandnormalinterpolationispresented.Analgorithmtoconstructthediscreteinterpolationisalsopresented,whichhasthetimecomplexityO(NlogN),whereNinthenumberofscatteredpoints.

简介：Aminopropyl,ethylenediamine,ethenylandglycidoxygroupsfunctionalizednanoparticles,withaveragediametersrangingfrom4to6nmandcontaining1.17mmolofgroups/g,arereadilyobtainedfromnanodiamondsmodifiedwithsilanecouplingagent.Forthestudyofthesenanoparticles,TEM,IRS,XPS,andTGanalysismethodshavebeenused.

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简介：Thetimeevolutionofoxygenplasmatreatedpolystyrene(PS)surfaceswasinvestigateduponstoringthemintheairundercontrolledhumidityconditions.Themethodsofwatercontactangle,X-rayphotoelectronspectroscopy(XPS),sumfrequencygeneration(SFG)vibrationalspectroscopy,andatomicforcemicroscopy(AFM)wereusedtoinferthesurfacepropertiesandstructure.ChemicalgroupscontainingoxygenwereformedonthePSsurfacewiththeplasmatreatment,demonstratedbywatercontactangleandXPS.Thesurfacepolaritydecayedmarkedlyontime,asassessedbysteadyincreaseinthewatercontactangleasafunctionofstoragetime,fromzerotoaround60°.Theobserveddecayisinterpretedasarisingfromsurfacerearrangementprocessestoburyingpolargroupsawayfromtheuppermostlayerofthesurfaces,whichisincontactwithair.Ontheotherhand,XPSresultsshowthatthechemicalcompositioninthefirst3nmsurfacelayerisunaffectedbythesurfaceaging,andthedepthprofileofoxygenisessentiallythesamewithtime.ApossiblechangeofPSsurfaceroughnesswasexaminedbyAFM,anditshowedthattheincreaseofwatercontactangleduringsurfaceagingcouldnotbeattributedtosurfaceroughness.Thus,itisconcludedthatsurfaceagingisattributabletosurfacereorganizationandthemotionofoxygencontaininggroupsisconfinedwithintheXPSprobingdepth.SFGspectroscopy,whichisintrinsicallyinterface-specific,wasusedtodetectthechemicalstructureofPSsurfaceatthemolecularlevelaftervariousagingtimes.Theresultsareinterpretedasfollows.DuringtheagingoftheplasmatreatedPSsurfaces,theoxygencontaininggroupsundergoreorientationprocessestowardthepolymerbulkand/orparalleltothesurface,whiletheCH2moietystandsuponthePSsurface.Ourresultsindicatethatthesurfaceconfigurationchangesdonotrequirelargelengthscalesegmentalmotionsormigrationofmacromolecules.Motionsthatareresponsibleforsurfaceconfigurationchangescoul