简介：Wedemonstrateapassivelymode-lockedall-fiberlaserincorporatingapieceofgraded-indexmultimodefiberasamode-lockingmodulatorbasedonanonlinearmultimodalinterferencetechnique,whichgeneratestwotypesofcoexistinghigh-energyultrashortpulses(i.e.,theconventionalsoliton(CS)andthestretchedpulse(SP))TheCSwithpulseenergyashighas0.38nJisobtainedatthepumplevelof130mW.Whenthepumpincreasesto175mW,thehigh-energySPoccursatasuitablenonlinearphasebiasanditspulseenergycanreach4nJata610mWpump.ThepulsedurationsofthegeneratedCSandSPare2.3psand387fs,respectively.Thetheoryofnonlinearfiberoptics,single-shotspectralmeasurementbythedispersiveFourier-transformtechnique,andsimulationmethodsbasedontheGinzburg–LandauequationareprovidedtocharacterizethelaserphysicsandrevealtheunderlyingprinciplesofthegeneratedCSandSP.Aroguewave,observedbetweentheCSandSPregions,mirrorsthelaserphysicsbehindthedynamicsofgeneratingahigh-energySPfromaCS.Theproposedall-fiberlaserisversatile,cost-effectiveandeasytointegrate,whichprovidesapromisingsolutionforhigh-energypulsegeneration.