针对近年来发展的提高工件疲劳寿命的激光冲击强化技术，采用一级谐振级8级放大级的系统结构和模块化设计方法，研制出了激光冲击强化用大能量、短脉宽、高频率的Nd:YAG脉冲固体激光器，分析了激光器的设计方案、激光光路布置特点，并对其技术指标进行了测试。在预热20 min后、环境温度变化小于2 ℃的情况下，单脉冲最大输出能量达25 J，能量不稳定度小于3%，脉宽在16～20 ns范围内连续可调，脉宽不稳定度小于±1 ns，光束发散角不超过2.5 mrad，重复频率达5 Hz。为进一步验证激光器的性能，对TC4钛合金进行了激光冲击强化试验，大幅度提高了TC4钛合金试件表面的残余压应力，测试和试验结果均表明，激光器的各项性能良好。

For the laser peening technology which is a recently-developed surface treatment method designed to improve the fatigue life of mechanical parts, using a oscillation eight-stage amplified system structure and the modular design method, high-energy, short-pulse and high-frequency Nd:YAG solid-state lasers are developed. Design scheme of the laser and the characteristics of laser beam transmission are presented and discussed. At ambient temperature which changes less than 2 ℃ and after 20 min of warm-up, the technical parameters such as the maximum single pulse energy of 25 J, energy instability less than 3%, pulse width which can be continuously adjustable between 16 ns and 20 ns, pulse width instability less than ±1 ns, beam divergence less than 2.5 mrad, and the maximum single frequency of 5 Hz are achieved. To further verify the performance of the lasers, a TC4 titanium alloy work-piece is tested with the Nd:YAG lasers. The tested results show that the compressive residual stress is greatly improved and the performance of the lasers is excellent.