简介:Multielectrodesemiconductorlasersarestudiedviatheraymethod.TheexpressionoftheoutputphotonnumberofN-electrodesemiconductorlasershasbeenderivedforthefirsttime.WhenN=1or2,theexpressionoftheoutputphotonnumberfitsinthatofone-electrode(general)ortwo-electrodesemiconductorlasersperfectly.
简介:Themeasurementtechniquesoffemtosecondspectroscopyareeffectivemethodtoinvestigateultrafastdynamics,theyarewidelyusedinthefieldsofphysics,chemistryandbiology.Inthispaper,theprinciple,experimentsetupandtheapproachestodealwiththeexperimentdatawerepresented.Thendifferentmeasurementtechniquessuchastransientabsorptionspectroscopy,photonechoes,opticalKerreffectanddegeneratefour-wavemixingwereexplainedwithspecialexamples.Atlast,theapplicationprospectofmeasurementtechniquesoffemtosecondspectroscopywasforecasted.
简介:Theuseofultra-highintensitylaserbeamstoachieveextremematerialstatesinthelaboratoryhasbecomealmostroutinewiththedevelopmentofthepetawattlaser.Petawattclasslasershavebeenconstructedforspecificresearchactivities,includingparticleacceleration,inertialconfinementfusionandradiationtherapy,andforsecondarysourcegeneration(x-rays,electrons,protons,neutronsandions).Theyarealsonowroutinelycoupled,andsynchronized,tootherlargescalefacilitiesincludingmegajoulescalelasers,ionandelectronaccelerators,x-raysourcesandz-pinches.Theauthorsofthispaperhavetriedtocompileacomprehensiveoverviewofthecurrentstatusofpetawattclasslasersworldwide.Thedefinitionof‘petawattclass’inthiscontextisalaserthatdelivers>200TW.
简介:Wereviewrecentadvancesinthefieldofquantumdotlasersonsilicon.Asummaryofdeviceperformance,reliability,andcomparisonwithsimilarquantumwelllasersgrownonsiliconwillbepresented.Weconsiderthepossibilityofscalable,lowsize,weight,andpowernanolasersgrownonsiliconenabledbyquantumdotactiveregionsforfutureshort-reachsiliconphotonicsinterconnects.
简介:Inthiswork,ahybridstructureconsistingofamulticomponentgermanateglassmicrospherecontainingbismuthasagainmediumisproposedandpresented.Thebismuth-dopedgermanateglassmicrosphereswerefabricatedfromaglassfibertipwithnoprecipitationofthebismuthmetal.Couplingwithafibertaper,thebismuth-dopedmicrospheresingle-modelaserwasobservedtolaseataround1305.8nmusing808nmexcitation.Thelowthresholdofabsorbedpumppowerat215μWmakesthismicrolaserappealingforvariousapplications,includingtunablelasersforarangeofpurposesintelecommunication,biomedical,andopticalinformationprocessing.
简介:Wepresenttheworkflowofthedesign,realizationandtestingofdeformablemirrorssuitableforhighpowerdiodepumpedsolid-statelasers.Itstartswiththestudyoftheaberrationtobecorrected,andthenitcontinueswiththedesignoftheactuatorspositionandcharacteristic.Inthispaper,wepresentandcomparethreedeformablemirrorsrealizedformulti-Jlevellaserfacilities.Weshowthatwiththesamedesignconceptitispossibletorealizedeformablemirrorsforothertypesoflasers.Asanexample,wereporttherealizationofadeformablemirrorforfemtosecondlasersandforaCWCO2laser.
简介:Asmid-infrared(MIR)lasersshownumerousapplicationsinthefieldofdefense,medical,materialsprocessing,andopticalcommunications.InvestigationonMIRRamanfiberlasers(RFLs)increasinglybecomesahottopic.Comparedwiththetraditionalsilicafibers,fluorideandchalcogenideglassfiberspossesshighernonlinearcoefficientsandexcellentMIRtransmittances.Inthisarticle,thelatestdevelopmentsoftheMIRRFLsusingfluorideandchalcogenideglassfibersasgainmediaareintroduced,respectively.ThisreviewarticlemainlyfocusesonthedevelopmentsofMIRRFLsinaspectsofoutputwavelength,outputpower,andopticalefficiency.Besides,theprospectofMIRRFLsisalsodiscussed.
简介:Ananalysissolutionofrateequationisderivedforverticalcavitysurface-emittinglasers.BasedontheenhancedspontaneousemissioncausedbyVCSELsandinfluenceofnonradiativerecombination,therelationbetweenoutputpropertiesandstructuralparametersofmulti-quantumwells(MQWs)isobtanined.Itwasfoundthatthecharacteristiccurveofa"thresholdless"laserisstronglynonradiativedepopulation-dependent.Whenthenonradiativedepopulationisnozero,thelight-currentcharacteristicisnotlinearlyevenforanidealclosedmicrocavity.Thelightoutputisincreasedbytheenhancedwellnumberandbythereducedwidth.Inparticular,alowerthresholdcurrentdensityforMQWsstructureintheshortcavityisrealizedbyus,meanwhilethesharpnessofthevariationdependsonspontaneousemissionfactor.
简介:AlineararrayofNmutuallycoupledsingle-modelasersisinvestigated.ItisshownthattheintensitiesofNlasersarechaoticallysynchronizedwhenthecouplingbetweenlasersisrelativelystrong.Thechaoticsynchronizationofintensitiesdependsonthelocationofthelasersinthearray.Thechaoticsynchronizationappearsbetweentwooutmostlasers,thesecondtwooutmostlasers,etc.Thereisnosynchronizationbetweennearestneighborsofthelasers.IfthenumberofNisodd,themiddlelaserisneversynchronizedbetweenanylasers.ThechaoticsynchronizationofphasesbetweennearestlasersinthearrayisexaminedbyusingtheanalyticsignalandtheGaussianfiltermethodsbasedonthepeakofthepowerspectrumoftheintensity.Itcanbeseenthatthemessageofchaoticintensitysynchronizationisconveyedthroughthephasesynchronization.
简介:Quantumdotlasershaveexcellentcharacteristicssuchastimperaturestabilityofthresholdcurrentandultra-highmaterialgain.Quantumdotstructuresfabricatedbyself-organizedgrowthhavehighcrystallineperfection,highquantumyieldofradiativerecombinationandhighsizehomogeneity.Mainadvantagesandoperatingpropertiesofquantumdotalsersfabricatedbyself-organizedgrowtharebrieflyintroduced.
简介:Whenexposedtointenseelectromagneticfields,thequantumvacuumisexpectedtoexhibitpropertiesofapolarizablemediumakintoaweaklynonlineardielectricmaterial.Variousschemeshavebeenproposedtomeasuresuchvacuumpolarizationeffectsusingacombinationofhigh-powerlasers.Motivatedbyseveralplannedexperiments,weprovideanoverviewofexperimentalsignaturesthathavebeensuggestedtoconfirmthispredictionofquantumelectrodynamicsofrealphoton–photonscattering.
简介:InGaAsP/GaAsSCHSQWlaershavebeenpreparedbyLPMOCVD.Thedependenceofthresholdcurrentdensityoncavitylengthwasexplained.Laserdiodesarecharacterizedbytheoutputpowerof1W20W,thresholdcurrentdensity(Jth)of330A/cm^2to450A/cm^2andexternaldifferentialquantumefficiency(ηd)of35%to75%,andthesecharacteristicsareingoodagreementwiththedesignedrequirement.
简介:Recentprogressonrare-earthdopedpolycrystallineYAGtransparentceramicshasmadethemanalternativenovelsolid-statelasergainmaterial.Inthispaper,wepresentresultsofourresearchonpolycrystallineRE:YAGtransparentceramics.HighopticalqualityYAGceramicsdopedwithvariousrare-earth(RE)ionssuchasNd3+,Yb3+,Er3+,Tm3+,andHo3+havebeensuccessfullyfabricatedusingthesolid-statereactivesinteringmethod.Highlyefficientlaseroscillationsofthefabricatedceramicsaredemonstrated.
简介:Ashortoverviewofthetheoryofaccelerationofthinfoilsdrivenbytheradiationpressureofsuperintenselasersispresented.Asimplecriterionforradiationpressuredominanceatintensitiesaround5×1020Wcm-2isgiven,andthepossibilityforfastenergygainintherelativisticregimeisdiscussed.
简介:Therelationshipbetweengainandcarrierdensityisanalysed.Inthequantumwell(QW)lasers,initially,thegainincreasesrapidlywiththecarrierdensityandthenstartstosaturate.ItcanbeseenthatQWlasershaveahigherdifferentialgainbecauseofthestep-likestatedensity,andthatthegainsaturatesathighercarrierdensitiesbecauseoftheconstantstatedensityofthelowestsubband.Itisshownthatsimpleogarithmicgain-carrierdensityismoreaccuratethanthetraditionallinearizedformforaQWlaser.
简介:Thepropertiesofaseriesofphasemeasurementtechniques,includinginterferometry,theHartmann–Shackwavefrontsensor,theknife-edgetechnique,andcoherentdiffractionimaging,aresummarizedandtheirperformanceinhighpowerlaserapplicationsiscompared.Theadvantages,disadvantages,andapplicationrangesofeachtechniquearediscussed.