相位校正器波前拟合误差仿真分析

Simulation of Wavefront Fitting Errors of Phase Corrector

在自适应光学系统中,波前拟合误差直接影响到相位校正器的校正效果。在仿真分析中,作为相位校正器的变形镜,其面形影响函数通常采用高斯函数近似。以高斯型面形影响函数为基础,利用最小二乘法,通过仿真计算分析了波前拟合误差与入射波前空间频率、驱动器密度、高斯指数、交连值等变形镜主要参数的关系。结果表明,变形镜对低空间频率波前具有较好的补偿能力,且驱动器密度是波前补偿能力的决定因素,增大高斯指数和交连值一定程度上有利于波前的补偿,并对其原因进行了阐释。存在一类特殊情况,当入射波前的零点恰好通过各变形镜所在位置,补偿拟合基本失效,应注意避免。

In the adaptive optical system, the fitting errors of wavefront impact correct effect of phase corrector directly. In simulation, as phase corrector of system, the deformable mirror＇s influence function generally was used with the Gaussian function. In this paper, based on the Gaussian function and least squares fit, we simulated and an- alyzed the relation between the fitting errors of wavefrent and the deformable mirror＇s parameters, such as actuator density, Gaussian index and coupling. The simulation results show that the deformable mirror can fit low - frequency component better rather than high - frequency component, and actuator density is the decisive factor of wavefront compensation. Increasing the Gaussian index or the coupling profits decreasing the fitting errors. A case should be a- void when the zero positions of incident wavefront are concurrent with actuator that causes failure of compensation.