重频可调高功率绿光皮秒激光器  

Tunable Repetition-rate High Power Picosecond Green Laser

作　　者：徐思志 夏瀛 高瑜博 刘星 欧阳德钦 陈业旺 吴旭 徐方华 郭丽 赵俊清 郭春雨[4] 吕启涛 阮双琛 XU Sizhi;XIA Ying;GAO Yubo;LIU Xing;OUYANG Deqin;CHEN Yewang;WU Xu;XU Fanghua;GUO Li;ZHAO Junqing;GUO Chunyu;LV Qitao;RUAN Shuangchen(Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes,Shenzhen Technology University,Shenzhen 518118,China;Sino-german College of Intelligent Manufacturing,Shenzhen Technology University,Shenzhen 518118,China;Han's Laser Technology Industry Group Co.Ltd.,Shenzhen 518103,China;Shenzhen Key Laboratory of Laser Engineering,College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China)

机构地区：[1]深圳技术大学先进光学精密制造技术广东普通高校重点实验室,深圳518118 [2]深圳技术大学中德智能制造学院,深圳518118 [3]大族激光科技产业集团股份有限公司,深圳518103 [4]深圳大学物理与光电工程学院深圳市激光工程重点实验室,深圳518060

出　　处：《光子学报》2023年第9期29-36,共8页Acta Photonica Sinica

基　　金：国家重点研发计划(No.2022YFB3605800);国家自然科学基金(No.62275174,62105225);深圳市高等院校稳定支持计划(No.20220719104008001);深圳新引进高端人才财政补助科研启动项目(No.GDRC202106);深圳市技术攻关重点项目(Nos.JSGG20190819175801678,JSGG20191129105838333)。

摘　　要：采用多级串联的主振荡放大技术,将SESAM锁模的种子光通过多级串联端泵Nd∶YVO_(4)晶体放大,产生平均功率为148.7 W、重复频率500 kHz~4 MHz、脉冲宽度8 ps的1064 nm基频光,同时开展了LBO晶体高效率二倍频的研究。通过优化相位匹配,实现了平均功率为95 W的532 nm皮秒激光输出,光-光转换效率达65%,光束质量因子M_(X)^(2)=1.27/M_(Y)^(2)=1.42,6 h功率抖动均方根低于0.8%。该绿光皮秒激光系统具有平均功率高、转换效率高、光束质量好、稳定性高、重频可调等优点,可以被作为皮秒激光加工系统的光源,被应用于科学研究和工业加工领域。In this paper,an 1064 nm,148.7 W,8 ps laser is obtained through a multi-stage end-pumped Nd:YVO_(4) solid-state laser amplification system.Further a 1mm-diameter spot is coupled to a LBO crystal for frequency doubling,and a 95 W,6.43 ps laser output is obtained at 532 nm,with a tunable Pulse Repetition Frequency(PRF)of 500 kHz~4 MHz.The Nd∶YVO_(4) Master Oscillator Power Amplifier(MOPA)consists of a high-power oscillator stage,fiber pre-amplifier and four end-pump amplifier stages.The seed is an all-fiber laser mode-locked by SESAM with a pulse duration of 7.8 ps and PRF of 20 MHz.The Acoustic Optical Modulator(AOM)is used for reducing the PRF to realize a higher peak power.The end-pump power amplifier is a four-stage free-space bulk amplifier based on neodymiumdoped yttrium vanadate(Nd∶YVO_(4))crystals for high-efficiency frequency conversion.It has a high polarization-dependent gain spectrum due to the birefringence of the uni-axial YVO_(4) crystal.Each amplifier is comprised of a 0.3%doped a-cut Nd∶YVO_(4) crystal having dimensions of 4 mm×4 mm×15 mm and is mounted on a water-cooled heat sink.All amplifiers are end-pumped by a fiber-coupled 878.6 nm(400μm core,NA=0.22)Laser Diode(LD),instead of conventional 808 nm LD,to reduce the degradation of the beam quality by thermal effects.The first amplifier stage is a double-pass configuration and increases the signal average power to 13 W for a 65 W pump light,while the second amplifier stage is a single-pass and scales up to 56 W of average power for a 115 W pump light.To match the amplified light with the pump light of the third stage,a lens of 80 mm focal length is added between the second stage and the third stage.Finally,56 W,2 MHz infrared(1064 nm)8.08 ps output with M2<1.5 is obtained.Then,the 56 W infrared picosecond laser is used as the source of the pre-amplification,and after shaping,it is focused to the third and fourth-stage amplifying module.This module uses two 115 W LD pumps with a center wavelength of 878.6 nm to pump two Nd∶YVO_(4) cryst

关 键 词：绿光皮秒 皮秒激光器 二次谐波产生 固体放大器 LBO晶体 

分 类 号：TN248[电子电信—物理电子学]