简介：Ahigh-powerpulsedpumpmethodisproposedtoobtainahigh-energyoutputwithanimprovedsignalto-noiseratio(SNR)duringpulseamplification.Basedonnumericalanalysis,theytterbium-dopedfiberamplifiersarecomparedunderdifferentpumpingconditions.Atthesamesignalgain,theoutputusingthehigh-powerpulsedpumpshowsgreatSNRimprovementandreducedoutputsignaldistortion,comparedwithacontinuous-wavepumpandalow-powerpulsedpump.Byadjustingthepumpparameters,theamplifiercanachievetheoptimaloutputSNRwithoutsacrificingthesignalgain.Webelievethatthehigh-powerpulsedpumpschemeisverysuitableforthehigh-energynanosecondpulseamplification,whichhasahighSNRrequirement.

简介：Photoniccrystalfibers(PCFs)withasteppedraised-coreprofileandonelayerequallyspacedholesinthecladdingareanalyzed.Usingeffectiveindexmethodandconsideringaraisedsteprefractiveindexdifferencebetweentheindexofthecoreandtheeffectiveindexofthecladding,weimprovethecharacteristicparameterssuchasnumericalapertureandV-parameter,andreduceitsbendinglosstoaboutonetenthofaconventionalPCF.ImplementingsuchastructureinPCFsmaybeonestepforwardtoachievelowlossPCFsforcommunicationapplications.

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).