在高功率激光器中采用相位共轭谐振腔技术可以补偿动态波前像差,在校正畸变的输出光束方面有极其重要的应用。分析了相位共轭腔的模式结构特性及稳定性,在实际高功率激光器中采用相位共轭谐振腔,使得激光系统的光束质量得到了极大改善。通过实验数据分析,提出在激光器系统中描述光束质量只用PV值和RMS值来量度是不足的,并利用结合光束环围能量分布图像和平均离焦系数来评价系统光束质量。实验结果表明,采用相位共轭谐振腔使得焦平面环围能量更为集中,同时平均离焦系数更接近零,结合上述方法评价系统光束质量更具实际意义。

The dynamic wavefront aberrations can be compensated, and the output beam can be aligned by using phase conjugated resonator for high power lasers. This article gives a brief analysis of the mode structure property and stability of phase conjugated resonator, and the laser beam quality has been greatly improved in actual high power laser with phase conjugated resonator. Through the analysis of experimental data, in the laser system beam quality is described insufficiently only using the measurement value of PV and RMS, and we propose a way to evaluate system beam quality with the use of combined the beam encircled energy distribution image and the average defocusing coefficient. The experimental results show that, the method using phase conjugated resonator makes that the actual beam encircled energy distribution image is more focused, and the average defocusing coefficient is close to 0. Finally, the evaluation of the beam quality combined with the above method has more practical significance.