径向剪切干涉波面重构的数值模拟分析

Numerical simulation and analysis of wavefront reconstruction in radial shearing interference

径向剪切干涉仪所采集到的干涉图并不直接反映原始待测波面信息,为了获得原始待测波面信息,波面重构是必要的。推导了波面重构的迭代算法,并用Matlab分别对径向剪切中不同迭代次数、不同剪切比的波面重构迭代算法进行了数值模拟,得出以下结论：合适的剪切比可以简化迭代运算,提高运算速度;与小畸变波面重构相比,残差波面PV值达到相同精度时,大畸变波面重构需要更多的迭代次数。待测波面的PV值大于10λ时,剪切比应在0.7以上,PV值大于6λ小于10λ,剪切比在0.5-0.7之间,PV值小于6λ,剪切比小于0.5。

In order to acquire the original wavefront information in radial shearing interferometry,wavefront reconstruction is necessary, the iterative algorism for wavefront reconstruction was deduced in this paper, based on which an numerical simulation using Matlab with different iteration number and shearing ratio was conducted. The simulation comes to the following conclusion： Properly selection of the shearing ratio can simplify the computational complexity. Compared with the small distortion wavefront reconstruction, more but appropriate iteration number in large distortion wavefront reconstruction is needed. Preferred shearing ratios for different measured wavefront PV values are summarized as follows：a. if WPV10λ, beta0.7; b. if 6λWPV10λ, 0.5beta0.7; c. if WPV6λ, beta0.5.