简介：Theinfluenceofcircularapertureontheintensityofhigh-orderharmonicgeneration(HHG)withintensefemtosecondlaserpulsewasstudiedbothexperimentallyandtheoretically.TheintensityvarietyofHHGwiththediameterofcircularaperturewasobservedinpulsedArgas.TheresultwasdiscussedandinterpretedintermsofthetheoryofHankeltransform.ItisfoundthatusingtheGaussianbeamtruncatedbyanaperturecouldenhancetheconversionefficiencyofHHGatcertainconditions.

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

简介：Alightpurplishredsapphireisheattreatedinanairtightcrucible.Thesamplechangeslittleincolorafterreceivingheattreatmentat1100°C,butturnstolightblueandblueafterbeingtreatedat1200°Cand1300°C,respectively.Beforeheating,theUV-VISabsorptionspectraofthesamplearedominatedbythe551nmbroadabsorptionbandcontributedbythed-electrontransition~4A_2→~4T_2ofCr~(3+).Afterheating,theUV-VISabsorptionspectraaredominatedbythe563nmbroadabsorptionbandcontributedbytheintervalencechargetransferofFe~(2+)-Ti~(4+).ThexrayphotoelectronspectroscopytestrevealsthattheFe~(2+)andTi~(4+)ioncontentsincreasewithincreasingtemperature.ThesapphirechangingfromlightpurplishredtoblueintheheatingprocessisowingtothefactthattheFe~(2+)andTi~(4+)contentsgrowandtheintervalencechargetransferofFe~(2+)-Ti~(4+)selectivelyabsorbsUV-VISlight.

简介：Theself-assembledInAs/GaAsquantumdots(QDs)withextremelylowdensityof8×10~6cm~(-1)areachievedusinghighergrowthtemperatureandlowerInAscoveragebylow-pressuremetal-organicchemicalvapourdeposition(MOVCD).Asaresultofmicro-photoluminescence(micro-PL),forextremelylowdensityof8×10~6cm~(-1)InAsQDsinthemicro-PLmeasurementsat10K,onlyoneemissionpeakhasbeenachieved.ItisbelievedthattheInAsQDshaveagoodpotentialtorealizesinglephotonsources.

简介：HighorderBraggscattering(M=2andM=3)operationsofthedistributedfeedbackdyedopedsol-gelsilicalasersareachievedusingthesecondharmonicoutputofaNd:YAGlaserasthepump.Laserlinewidthoflessthan0.06nmandconversionefficiencyof0.7%forM=3and11%forM=2aremeasured.Wavelengthtuningofabout15nmaroundtheemissioncenterhasbeenrealizedbyvaryingtheintersectionangle.

简介：我们基于用与一个二进制树分类器相结合的高顺序的周期的cumulant察觉到压缩建议调整格式鉴定的一个方法。通过计算，pretreated乐队信号的第四顺序的周期的cumulant，它被获得由压缩了很与采样率察觉到不到Nyquist采样值，为分类的特征向量被提取。模拟与多重阶段移动调音和多重照振幅调整的不同调整格式在光协调纤维通讯系统被执行。结果显示这个方法能正确地并且高效地识别这些调整格式。同时，建议方法对激光阶段噪音和信号噪音感觉迟钝。

简介：Influencesofthescatteringphasefunctionsonspatiallyresolveddiffusereflectancefromahomogenoussemi-infinitemediumclosetosourcearestudiedwithMonteCarlosimulation.Itisshownthattheinfluencesofopticalparametershigherthanthesecondorderonthediffusereflectancearequiteweakintheregionfrom0.3toseveraltransportmeanfreepatheswhenHenyey-Greensteinphasefunctionoracombinedphasefunctionoftwoparametersareused.ButthisinfluencemaybesubstantialifthedoubleHenyey-Greensteinfunctionisusedtodescribethescatteringpropertyoftissue.

简介：

简介：

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

简介：Intense-laser-inducedabove-thresholdionizationofaboundelectronintocontinuumstateswithlowenergyisinvestigatedinthecontextofthestrong-fieldapproximationthatallowsforoneactofrescatteringoftherevisitingelectron.Thequantumorbitsforforwardandbackwardscatteringareevaluatedandgeneralizedtoarbitraryscatteringangles.Thevelocitymapoftheliberatedelectronexhibitsthewell-knownlow-energystructureaswellasotherfeaturesoffthepolarizationaxis.

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

简介：InthisLetter,wefocusonthetheoreticalanalysisoftherelativisticenergyandangulardistributionsoftheejectedphotoelectronsduringtherelativistictunnelionizationofatomsbyintense,circularlypolarizedlight.Wemakeasmallmodificationofthegeneralanalyticalexpressionsforthesedistributions.Theroleoftheinitialmomentum,theponderomotivepotential,andtheStarkshiftareconsidered.Wealsopresentthemaximalangleofelectronemission.

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

简介：Thisletterpresentsalowcostsolutionforwavelengthdivisionmultiplexedorthogonalfrequencydivisionmultiplexedpassiveopticalnetwork(WDM-OFDM-PON)withwidelytunableopticalfilterandlinearsmallform-factorpluggable(SFP)module.With9-nmtunablerangefrom1551to1560nm,thetunablefiltercansupportupto10-channel100-GHzspacingWDMPONsystem.Alinearavalanchephotodiode(APD)basedSFP+moduleisdesignedforopticalOFDMsignaldemodulation,whichcanprovidebetterreceiverperformancecomparedwithlimitingAPDmodule.Experimentalresultsshowthat～34dBpowerbudgetcanbeachievedin4×5-GbpsWDM-OFDM-PONsystem,whichcansatisfythetransmissionrequirementsofnextgenerationPONsystem.

简介：Squeezedstateoflightexploresanewerainnoiselesscommunicationanddataprocessingrecentlybreakingthequantumlimitofnoise.Weproposeanewmechanismofmodulatinganamplitude-squeezedsignalwiththeinstantaneousintensityvariationofacoherentsignal.Themodulatingsignalisacoherentlightwheretheamplitude-squeezedlighttakestheroleofacarriersignal.

简介：A100-Gb/shigh-speedopticaltransmitterisproposedandexperimentallydemonstrated.Basedonfrequency-quadruplingtechnique,twosub-channelswithafixed50-GHzspacingareobtainedfromonelasersource.Usingreturn-to-zerodifferentialquadraturephase-shiftkeying(RZ-DQPSK)modulationformatandpolarizationmultiplexing(PolMux),onlylow-speedelectronicdevicesof12.5GHzareneededforthe100-Gb/stransmitter.Thiseliminatestheneedofultrahigh-speedoptoelectronicdevicesandthusgreatlyreducesthecost.Theexperimentalresultsshowthatthistransmittercanachievegoodperfor-manceindispersiontoleranceofa25-kmsinglemodefiber(SMF).