高功率平面波导皮秒激光放大器  

High-Power Planar Waveguide Picosecond Laser Amplifier

作　　者：王金川 何平 曹海霞 汪丹[1,2] 王君涛[1,2] 周唐建[1,2] 尚建力[1,2] 高清松[1,2] Wang Jinchuan;He Ping;Cao Haixia;Wang Dan;Wang Juntao;Zhou Tangjian;Shang Jianli;Gao Qingsong(Institute of Applied Electronics,China Academy of Engineering Physics,Mianyang 612900,Sichuan,China;Key Laboratory of Science and Technology on High Energy Laser,China Academy of Engineering Physics,Mianyang 612900,Sichuan,China;Graduate School,China Academy of Engineering Physics,Beijing 100088,China)

机构地区：[1]中国工程物理研究院应用电子学研究所,四川绵阳612900 [2]中国工程物理研究院高能激光科学与技术重点实验室,四川绵阳612900 [3]中国工程物理研究院研究生院,北京100088

出　　处：《中国激光》2023年第2期43-49,共7页Chinese Journal of Lasers

基　　金：中物院创新发展基金(C-2021-CX20210030)。

摘　　要：设计了一种Nd∶YAG平面波导皮秒激光放大器。光纤激光器提供重复频率可调的皮秒种子源,Nd∶YAG平面波导激光放大器采用后端抽运方式,其抽运源工作模式为连续模式。当种子光的重复频率为24.46MHz、脉宽为11.7ps、注入功率为0.48W时,输出功率为228W,单脉冲能量为9.3μJ,光-光转换效率达到20.2%,导波方向和非导波方向的光束质量(M2)分别为1.4和4.6。当种子光的重复频率降低至25kHz时,输出平均功率为24.2W,单脉冲能量提升至0.97mJ,单脉冲能量放大倍率为4.9×104,表明放大系统具有较强的放大能力。根据理论计算,分析了进一步提高光-光转换效率和输出功率、抑制放大自发辐射(ASE)的方法。Objective High-energy,high-peak power,picosecond pulse lasers have broad application prospects in laser science research and industrial processing.The configuration of a master oscillator power amplifier(MOPA)is commonly used to obtain a high output power.In this case,a low-power oscillator with the desired characteristics is used as the seeder,whose radiation is injected into an amplifier to scale the output power or pulse energy,while other properties remain mostly unchanged.The planar waveguide can provide high seed light injection powers and high pumping power densities.Therefore,the planar waveguide lasers are a potential laser technology for obtaining picosecond pulse laser with high energy and high peak power.Methods A Nd∶YAG planar waveguide picosecond laser amplifier is designed.The seed is a fiber picosecond laser,which is amplified by a compactness amplifier with a Nd∶YAG planar waveguide as the gain medium to obtain a picosecond laser output.The small signal gain coefficient and power distributions at different positions within the planar waveguide are calculated using related theories.Finally,based on the results of theoretical calculations,a picosecond laser amplifier is designed and built,and the experiment is completed under different seed laser repetition frequencies.Results and Discussions To evaluate the amplification ability of the amplification system under different seed laser repetition frequencies,the seed source is operated at repetition frequencies of 24.46 MHz,4.89 MHz,2.038 MHz,1.019 MHz,500 kHz,200 kHz,99.4 kHz,49 kHz,and 25 kHz,and the output power is obtained as a function of the pump power(Fig.7 and Table 1).Once the seed light passes through the isolator and the beam expansion system,the single pulse energy injected into the slab is19.6 nJ.In the single-end pumped case,when the repetition frequency of the seed source is 24.46 MHz,the output power is 228 W,the single-pulse energy is 9.3μJ,the optical-optical conversion efficiency is 20.2%,and the beam quality(M~2)values in the

关 键 词：激光器 皮秒激光 平面波导 高峰值功率 

分 类 号：TN248.1[电子电信—物理电子学]