经过对四镜折迭腔细致的数值分析，发现只要腔参数选择得当，这类腔能实现大基模体积热稳运转。腔内适当大小的束腰光斑使倍频过程有较高的效率。实验验证了这一结果，最高倍频输出超过３２Ｗ，而且与同类传统的两镜直腔激光器相比，输出光束质量有显著的提高 After careful analysis of the four mirror folding chamber, it is found that the cavity can realize the thermal stability of the large base mold as long as the cavity parameters are properly selected. Cavity appropriate size of the beam spot multiplier process has a higher efficiency. The experimental results show that the maximum output frequency is over 32W, and the output beam quality is significantly improved compared with the conventional two-mirror straight-cavity laser