基于脉冲光泵浦的mJ级棒状Yb:YAG飞秒激光放大器(特邀)  

mJ-level pulses based on pulsed pumping with Yb:YAG-rod femtosecond laser amplifier(invited)

作　　者：冯汝毅 邹跃 郝静宇 王思佳[3] 刘博文 范锦涛[1] 胡明列 FENG Ruyi;ZOU Yue;HAO Jingyu;WANG Sijia;LIU Bowen;FAN Jintao;HU Minglie(Ultrafast Laser Laboratory&Key Laboratory of Optoelectronic Information Technology(Ministry of Education),School of Precision Instrument and Opto-electronics Engineering,Tianjin University,Tianjin 300072,China;Beijing Opto-Electronics Technology Co.,Ltd.,Beijing 100015,China;Qian Xuesen Laboratory of Space Technology,China Academy of Space Technology,Beijing 100094,China;Georgia Tech Shenzhen Institute,Tianjin University,Shenzhen 518071,China)

机构地区：[1]天津大学精密仪器与光电子工程学院超快激光研究室&光电信息技术教育部重点实验室,天津300072 [2]北京雷生强式科技有限责任公司,北京100015 [3]中国空间技术研究院钱学森空间技术实验室,北京100094 [4]天津大学佐治亚理工学院深圳学院,广东深圳518071

出　　处：《红外与激光工程》2025年第3期130-138,I0001,共10页Infrared and Laser Engineering

基　　金：国家重点研发计划项目(2021YFB3602600);国家自然科学基金项目(62227821)。

摘　　要：高功率泵浦引入的热效应是影响固体激光放大器实现高脉冲能量、高光束质量脉冲放大输出的因素,采用脉冲光泵浦的形式能够有效缓解热效应带来的影响。基于同步脉冲光泵浦方式,结合啁啾脉冲放大技术,仅通过单级棒状Yb:YAG双通行波激光放大,压缩后获得单脉冲能量为1.65 mJ、重复频率为1 kHz、脉冲宽度为623 fs、光束质量因子为M2X=1.13,MY2=1.14、2 h功率稳定性为0.85%(RMS)、10万个脉冲间能量稳定性为1.11%(RMS)的高光束质量飞秒激光输出。将其作为基频光注入到基于补偿板的三倍频系统中,通过优化基频光光斑尺寸以及晶体厚度,得到单脉冲能量为0.438 mJ、中心波长为344 nm的紫外飞秒激光,三次谐波的总转换效率高达26.5%。Objective Ultrafast laser with high power and high energy is widely used in industry and scientific research.The femtosecond laser power output of the mode-locked oscillator stage is usually low,and it is difficult to meet the application requirements,power amplification is performed in the subsequent amplifier stage.Compared with fiber amplifiers,solid state amplifiers have low nonlinear effects and high damage thresholds,so they can support higher energy femtosecond laser output.However,at the same time of obtaining high energy laser output,due to the thermal effect introduced by high power pumping,the beam quality is significantly reduced,and in some applications,the pulse energy is not required to be extremely high,only the mJ magnitude can be reached,and ask it has the characteristics of high beam quality,high pulse quality and high stability.Therefore,it is significant to study a compact single-stage solid-state amplifier,which can output mJ energy while maintaining a high level of beam quality.Methods Based on femtosecond mode-locked laser and all-fiber pre-amplifier stage,combined with chirped pulse amplification technology,a two-pass wave amplification system based on Yb:YAG is constructed.In order to reduce the influence of thermal effect on beam quality and improve pump efficiency,periodic signal modulation is applied to pump control current to realize synchronous pulse pumping with adjustable duty cycle.In order to control the size of the spot in the process of amplification,the self-reproducing optical path is designed and simulated according to the simulation results of thermal lens,and the numerical reference is provided for the selection of focal length parameters of the compensated lens(Fig.2).In order to obtain femtosecond laser output with high pulse quality,the pulse output near the transformation limit is obtained by optimizing the angle and distance of the grating and adjusting the second and third order dispersion values of CFBG.Based on the compressed femtosecond fundamental frequency ligh

关 键 词：固体激光器 飞秒激光 啁啾脉冲放大 频率转换 

分 类 号：TN248.1[电子电信—物理电子学]