高峰值功率高重复频率纳秒激光板条放大器  

Nanosecond Slab Laser Amplifier with High Peak Power and High Repetition Rate

作　　者：董雪岩 王浩竹 刘凯 寇扬 筵兴伟 刘自磊 李辛垒 杨培将 许彦 杨凤图 张成功 Dong Xueyan;Wang Haozhu;Liu Kai;Kou Yang;Yan Xingwei;Liu Zilei;Li Xinlei;Yang Peijiang;Xu Yan;Yang Fengtu;Zhang Chenggong(Institute of Optical Physics and Engineering Technology,Qilu Zhongke,Jinan 250104,Shandong,China)

机构地区：[1]齐鲁中科光物理与工程技术研究院,山东济南250104

出　　处：《中国激光》2025年第2期55-62,共8页Chinese Journal of Lasers

基　　金：山东省重点研发计划(2023CXPT028)。

摘　　要：介绍了一种高峰值功率和高重复频率的纳秒激光板条放大器。该放大器采用基于新型焊接工艺的混合冷却板条模块结构设计,同时结合了一种泵浦光角度可调的L形泵浦耦合结构,从而显著降低了板条晶体内部的温度梯度,有效抑制了晶体厚度方向上的热透镜效应。设计了基于板条晶体角度选通的三通放大结构,建立了板条激光放大器的速率方程,通过模拟和优化放大器的输出特性,提高了激光的提取效率。同时,通过优化放大级之间的像传递系统,进一步提升了放大激光的光束质量。当注入纳秒种子光的平均功率为380 W,且板条模块的泵浦功率达到15950 W时,该放大器实现了平均功率为4580 W、峰值功率为3.4 MW的激光输出。该板条激光放大器的重复频率为20 kHz,脉冲宽度为66.7 ns,光光转换效率达到了28.7%,光束参数乘积(BPP)为10mm·mrad。Objective High peak power and high repetition rate nanosecond lasers are widely applicable and exhibit high market prospect in laser welding,laser cutting,laser cleaning,and other fields owing to their high peak power and low processing thermal effect,which can effectively solve the issues related to the precision and mechanical properties of conventional processing methods.Under highaverage-power pumping,a thermal lens effect is generated,as the pump light is tightly concentrated on the laser gain medium.The processing method and quality are limited by the peak power and beam quality.To improve the peak power and beam quality of the laser,a pump-coupling structure with an adjustable pump angle and a hybrid cooling-slab module realized via a new welding process were designed in this study.A slab laser amplifier based on an angle gating structure is proposed,which offers the advantages of high peak power,high beam quality,and high conversion efficiency.Methods In this study,a high peak power and high repetition rate nanosecond-laser slab amplifier was investigated theoretically and experimentally.The hybrid cooling module was designed,and a new type of fusion welding technology was adopted,which effectively reduces the thermal lens effect and thermal distortion in the thickness direction of the slab crystal,realizes uniform heat dissipation,and improves the laser output power.To achieve a high power output,through efficient image transmission and by adopting aperture-filtering technology,we effectively corrected the optical aberration and reduced the free transmission of the beam,thereby improving the spot uniformity and maintaining a high beam quality.Additionally,an L-shaped optical-path pump-coupling structure with an adjustable pump light angle was designed.By designing an aspheric mirror and a trapezoidal waveguide,the pump light is uniformly pumped onto the large surface of the slab crystal,which effectively improves the pump coupling efficiency.The design of an adjustable 45°reflector frame can realize an

关 键 词：高峰值功率 高重复频率 纳秒激光 多通放大器 板条放大器 

分 类 号：TN202[电子电信—物理电子学]