径向剪切干涉术的标定算法研究

Study of Calibration Method of Radial Shearing Interferometry

径向剪切干涉术目前被广泛运用于波前检测，但其测量结果中不仅包括待测波前的实际相位信息，也包括剪切干涉仪自身的系统误差。通过平移待测元件获取其产生的透射波前在不同位置时的干涉条纹图所包含的相位信息，运用最大似然方法对多次采集的相位差进行线性组合分析和最大似然估计，将待测波前相位差与系统误差相位差分离。对该方法进行了模拟实验，结果表明最大似然法可以将系统误差相位差与待测波前相位差分离，实现对剪切干涉仪的标定，为提取和重建待测元件波前消除了系统误差的干扰。

Radial shearing interferometry has been widely used to test distorted wavefront. However, the result of wavefront measurement by using this technique includes two parts, one is the real phase information of wavefront under test and the other is the system errors in radial shearing interferometer. A calibration method of a radial shearing interferometer is presented. First of all, several fringe patterns of the phase difference distribution are obtained by a tested component with different positions. Then, the maximum likelihood method is used to combine the phase difference data and create a maximum likelihood function. After that, the wavefront under test and system errors can be separated. The simulation results show that the maximum likelihood method can deal with the issue of the calibration of a radial shearing interferometer. Furthermore, the method is used to reduce the effect of the system errors on extracting and reconstructing the wavefront under test.