High-energy 2 µm pulsed vortex beam excitation from a Q-switched TmLuYAG laser

722Vol.45,No.3/1February2020/OpticsLettersLetterHigh-energy2µmpulsedvortexbeamexcitationfromaQ-switchedTm:LuYAGlaserYingChen,1,†ManmanDing,1,†JianleiWang,1LiWang,1QiyaoLiu,2YongguangZhao,1,3,4,*YingLiu,2DeyuanShen,1,2ZhengpingWang,3XinguangXu,3ANDValentinPetrov41JiangsuKeyLaboratoryofAdvancedLaserMaterialsandDevices,JiangsuNormalUniversity,Xuzhou221116,China2JiangsuCollaborativeInnovationCentreofAdvancedLaserTechnologyandEmergingIndustry,JiangsuNormalUniversity,Xuzhou221116,China3StateKeyLaboratoryofCrystalMaterialsandInstituteofCrystalMaterials,ShandongUniversity,Jinan250100,China4MaxBornInstituteforNonlinearOpticsandShortPulseSpectroscopy,Max-Born-Str.2a,D-12489Berlin,Germany*Correspondingauthor:yongguangzhao@yeah.netReceived25November2019;revised1January2020;accepted1January2020;posted3January2020(Doc.ID384201);published30January2020Wereportonthefirst,tothebestofourknowledge,directgenerationofpulsedvortexbeamsat2µmfromaQ-switchedTm:LuYAGlaser.High-energyLaguerre–Gaussian(LG0,l)pulsedlaserbeamswithwell-definedhandednessareselectivelyexcitedthroughspatiallymatchedpumpgaindistributionandasymmetriccavitylosswithoutusinganyintracavityhandedness-selectiveopticalelements.Pulseenergiesof1.48mJfortheLG0,+1modeand1.51mJfortheLG0,−1mode,respectively,areachievedatarepetitionrateof500Hz.Thepulsedlaserbeamswithhelicalwavefrontsarepotentiallyusefulforstudyingorbitalangularmomentumtransformationdynamics,generationofmid-IRvortexbeams,andnanostructuringoforganicmaterials.©2020OpticalSocietyo