Yb:KYWInnoslab-AmplifierT.Mans',P.Ru8biildt!,J.Weiteuberg',G.Rctarius',D.Hoffmann',R.Poprawe'fJFraunhoferInstituteforLaserTechnology,2ChairforLaserTechnologyRWTHAachen,Steinbachstr.15,52074Aachentel.:+49(0)241/8906-379,jax:-121,e-mail:Torsten.Mans@ill.{raunhofer.deAmplificationbyInnoslabamplifiershasbeenappliedtoultrafastlaserpulsesformanyyears[I].Recentprogressinhighpowerlaserdiodesandanewpumpingscheme[2]madeapplicationofytterbiumdopedlasercrystalswhichsupportsubpicosecondpulsedurationspossible.AnInnoslabamplifierconsistsofathinslabcrystal(-IOxIOxlmnr'),whichiscooledonthelargefaces(Iuxlumnr')oftheslab.Thepumpradiationisfocusedinathinlinepropagatinglongitudinallythroughtheslab,i.e.indirectionoftheamplifiedlaserbeam.Thecavityaroundtheslabreproducesthebeamparametersoftheseedbeameachroundtripincombinationwitha(cylindrical)thermallensinonedirection.IntheotherdirectiontheslabcrystaldoesnotshowthermallenseffectsandthebeamexpandsbyaconstantmagnificationMeachroundtrip.UltrashortpulseexperimentswerecarriedoutwithaYb:KYWfs-oscillator(HighQLaserInnovationGmbH).MorethanP=400Woffs-radiationhavebeenextractedfromanInnoslabamplifiersetupapplyingYb:YAGashostmaterial[3].Thepulsesofr=682fsdurationwerenearlytransformlimited(rilv=0.348)withoutanycompression.NeverthelessgainnarrowingreducedthespectralbandwidthLUs=3.7omoftheoscillatortoLU=1.81ombehindtheamplifier.a)c1000b)~2ooa.Q:;3:Ps=3W2%Yb:KYW~00100a.E?~100.100\a.\0102010251030103510400110150200400600800Wavelengthi·lnm)PumppowerPplV\\1Fig.1:a)Comparisionofemissionspectrab)CalculatedoutputpowerofYb:KYWamplifierO-t-~-\=\Toenableshorterpulselengthstungstates(KYW,KGW)havebeenappliedaslaserhostsastheyexhibitabroaderemissionbandwidth(Fig.1a).Inafirststepnumericalsimulationandoptimizationofefficiencyandbeamqualityhavebeencarriedout.Calculationstookathreedimensionalmodelofthelasercrystalincludingthedistributionofpumpandseedradiationandtemperaturedependenceofinversionoftheytterbiumionintoaccount.ArbitrarilydistributedelectromagneticfieldsarepropagatedsolvingtheFresnelHuygensdiffractionintegral.DuetothelowergaincrosssectionofYb:KYWexpectedoutputpowersarebelowthevaluesachievedwithYb:YAG(Fig.lb)butwithsignificantlyreducedgainnarrowing.Firstexperimentalresultsincomparisiontothesecalculationswillbepresented.References[I]1.Giesekus,T.Mans,K.-M.Du,B.Braun,P.Loosen,R.Poprawe,\ConferenceonLasersandElectrooptics(CLEO),paperCTh13,(200I)[2]P.Ruhbuldt,T.Mans,D.Hoffmann,R.Poprawe,\Electrooptics(CLEO),paperCTuK5,(2008)[3]P.Rulsbuldt,H.-D.Hoffmann,T.Mans,\ofYblNNOSLABamplifiersbeyondlOOWaveragepower\ofSPlEVolume7193,paper7193-23,(2009)978-1-4244-4080-1/09/$25.00@2009IEEE
(二极管三极管)2009_Yb,KYW板条放大器
