基于自再现原理,利用菲涅耳基尔霍夫衍射积分方程,引入腔镜失调、激光介质上的增益分布以及光阑口径,采用本征矢量法分析了大口径平凹腔薄片激光器的本征模式,并计算了相应的光束质量因子M2。建立了千瓦级薄片激光系统和光纤扫描光斑诊断装置,开展了高功率激光输出特性研究。结果表明,在大口径高功率平凹腔中多个本征模式可同时起振,获得高功率激光输出,有较大的失调容限;输出功率随腔镜失调角度的增大而减小;失调容限随孔径光阑尺寸的减小而减小;失调引入了新的模式竞争,光束质量因子M2随腔镜失调角度的增大而变小。所得结果为高功率、高光束质量激光系统设计提供了有用参考。 Based on the self-reproducing principle, using the Fresnel Kirchhoff diffraction integral equation, introducing the misalignment of the cavity, the gain distribution on the laser medium and the aperture of the diaphragm, the eigenvalues ​​of large-caliber plano- Mode, and calculate the corresponding beam quality factor M2. A kilowatt-class lamellar laser system and optical fiber scanning spot diagnostic device were established, and the high-power laser output characteristics were studied. The results show that multiple eigenmodes can be excited simultaneously in a large-aperture and high-power plano-concave cavity, and high power laser output is obtained with large misalignment tolerance. The output power decreases with the increase of the misorientation angle. The offset tolerance decreases as the size of the aperture diaphragm decreases; the offset introduces a new mode competition, the beam quality factor M2 decreases with the increase of the angle of the mirror misalignment. The results provide a useful reference for high power, high beam quality laser system design.