简介：Unlikeatraditionalfiberlaserwithadefinedresonantcavity,arandomfiberlaser(RFL),whoseoperationisbasedondistributedfeedbackandgainviaRayleighscattering(RS)andstimulatedRamanscatteringinalongpassivefiber,hasfundamentalscientificchallengesinpulsingoperationforitsremarkablecavity-freefeature.Forthetimebeing,stablepulsedRFLutilizingapassivemethodhasnotbeenreported.Here,weproposeandexperimentallyrealizethepassivespatiotemporalgain-modulation-inducedstablepulsingoperationofcounterpumpedRFL.Thankstothegoodtemporalstabilityofanemployedpumpingamplifiedspontaneousemissionsourceandthesuperiorityofthispulsegenerationscheme,astableandregularpulsetraincanbeobtained.Furthermore,thepumphysteresisandbistabilityphenomenawiththegenerationofhigh-orderStokeslightispresented,andthedynamicsofpulsingoperationisdiscussedafterthetheoreticalinvestigationofthecounterpumpedRFL.ThisworkextendsourcomprehensionoftemporalpropertyofRFLandpavesaneffectivenovelavenuefortheexplorationofpulsedRFLwithstructuralsimplicity,lowcost,andstableoutput.

简介：Wereportanindex-coupleddistributedfeedbackquantumcascadelaserbyemployinganequivalentphaseshift(EPS)ofquarter-waveintegratedwithadistributedBraggreflector(DBR)atλ~5.03μm.TheEPSisfabricatedthroughextendingonesamplingperiodby50%inthecenterofasampledBragggrating.ThekeyEPSandDBRpatternarefabricatedbyconventionalholographicexposurecombinedwiththeopticalphotolithographytechnology,whichleadstoimprovedflexibility,repeatability,andcost-effectiveness.Stablesingle-modeemissioncanbeobtainedbychangingtheinjectioncurrentorheatsinktemperatureevenundertheconditionoflargedrivingpulsewidth.

简介：Forafullychaotictwo-dimensional(2D)microcavitylaser,wepresentatheorythatguaranteesboththeexistenceofastablesingle-modelasingstateandthenonexistenceofastablemultimodelasingstate,undertheassumptionsthatthecavitysizeismuchlargerthanthewavelengthandtheexternalpumpingpowerissufficientlylarge.Itistheoreticallyshownthattheseuniversalspectralcharacteristicsarisefromthesynergisticeffectoftwodifferentkindsofnonlinearities:deformationofthecavityshapeandmodeinteractionduetoalasingmedium.OurtheoryisbasedonthelinearstabilityanalysisofstationarystatesfortheMaxwell–Blochequationsandaccountsforsingle-modelasingphenomenaobservedinrealandnumericalexperimentsoffullychaotic2Dmicrocavitylasers.