采用正支虚共焦腔型对非链式脉冲DF激光器进行非稳腔参数设计并开展实验研究,通过与平凹型稳定腔的对比,揭示了非稳腔在压缩激光远场发散角、提升光束质量方面的显著优势。选取能体现远场能量集中度以及实际光束与理想光束偏移程度的衍射极限倍数β为光束质量评价参数,实验中以86.5%环围能量定义光斑大小,并利用90-10刀口法测量光斑尺寸。通过对不同放大率及模体积的9组非稳腔实验结果的对比,得到了设计优化非稳腔结构参数的规律。综合输出能量、远场发散角、衍射极限倍数β三方面因素,得到了最佳非稳腔参数为放大率M=1.89,后反射镜口径D=40mm,此时激光远场发散角(全角)为0.74mrad,β=1.35,输出能量为1.86J,峰值功率为16.4MW。 In this paper, the unbalanced cavity parameters of unbalanced confocal cavity DF are studied and the experimental research is carried out. The comparison between the stable cavity and the flat concave cavity shows that the unsteady cavity can reduce the divergence angle, Significant quality advantage. The diffraction multiple β which can reflect the far-field energy concentration and the degree of deviation of the actual beam from the ideal beam is selected as the beam quality evaluation parameter. In the experiment, the spot size is defined by the surrounding energy of 86.5%, and the spot size . By comparing the experiment results of 9 sets of unstable cavity with different magnification and mode volume, the law of designing and optimizing the parameters of unsteady cavity was obtained. The results show that the best unsteady cavity parameters are the magnification M = 1.89, the diameter of the rear reflector D = 40mm, and the far-field divergence angle of the laser beam (full-angle) Is 0.74 mrad, β = 1.35, the output energy is 1.86 J, the peak power is 16.4 MW.