激光辐照下非稳腔镜变形对激光模式的影响

 分析了正支虚共焦非稳腔中腔镜变形对激光模式的影响，采用时间离散化、快速傅里叶变换（FFT）和有限元分析(FEA)方法解决腔镜变形和激光模式两者之间的耦合问题。计算结果表明，随着激光器工作时间的增加，腔镜温升和变形相应增大，谐振腔模式变差，输出光场相位均匀性变差，呈现散焦现象，输出光束质量下降。实验验证了激光器输出光束质量随出光时间的延长而逐渐变坏。

Laser mode changing with deformation of resonator mirrors under irradiation

Influences on the mode of positive-branch confocal unstable resonator are analyzed,which is caused by deformation of resonator mirrors.The coupling relations between deformation of resonator mirrors and laser modes are solved by using methods of time discrete,fast Fourier transform(FFT) and finite element analysis(FEA).With the increasing working time of laser discreteness,the results of calculation show that temperature increment and deformation of resonator mirrors become serious,which causes decline of laser modes and beam quality.The uniformity of phase and dispersing appearance are discussed.The correlative experiments show that laser output beam quality becomes worse when the laser works longer.