低阶像差校正的压电驱动变形镜测试与仿真优化

光纤激光器输出光束带有波前畸变，制约了光学系统的性能和工作效率。搭建实验系统分析了超连续谱光纤激光器系统输出光束的像差特性，不同波长的滤波片测试像差均以离焦为主。根据这一特点制备了3单元单层横向压电驱动变形镜样镜,并进行特性测试。变形镜影响函数有限元仿真和实测吻合度可达77%以上，一阶谐振频率12.1 kHz。以实际像差为对象进行闭环仿真，校正精度达到0.77。另外，从校正精度及行程两个方面对变形镜进行了有限元优化仿真。结果9单元变形镜（有效口径7.5 mm）校正精度达到0.9左右。镜片与压电片厚度比存在最优值约0.3，行程可提升60%以上。
The fiber laser beam has wave-front aberration, which restricts the performance and efficiency of optic systems. The aberrations′ character of the super-continuum fiber laser beam was analyzed with a building experiment system, and defocus was the main ingredient. According to the character, a prototype of 3-element unimorph DM (unimorph deformable mirror) was manufactured and tested. The simulation accuracy of the influence functions is more than 77% and the frequency response is 12.1 kHz. The results of closed loop correction simulation show that the 3-element unimorph deformable mirror′s correction accuracy for the actual aberration is 0.77. Meanwhile, the finite element analysis is used to optimize the fitting accuracy and displacement. At last a 9-element unimorph DM with the aperture 7.5 mm can reach the accuracy level of about 0.9. The thickness ratio of the mirror and the piezoelectric disk is optimized about 0.3, which further promotes more than 60% of the initial displacement.