大剪切量干涉的二维波前重建

提出一种基于模式展开和最小二乘拟合的算法，可以从大剪切量差分波前快捷地重建原始的二维波前。在傅里叶模式展开理论的基础上，从横向剪切干涉获得的差分波前，通过最小二乘拟合，可以计算出待测波前的傅里叶变换系数，重建出原始波前。针对大剪切量带来的差分相位数据维数减小的问题，提出了数据预处理方法。这个算法解决了已有的傅里叶模式估计理论中要求剪切量等于采样间隔的限制，可以应用于大剪切量干涉条件下的二维波前重建。

Two-Dimensional Wavefront Reconstruction of Shearing Interferograms with Big Shears

A novel technique is proposed based on Fourier modal expansion and least-square fitting to reconstruct a two-dimensional wavefront from phase difference resulting from large shear. By using Fourier expansion, the Fourier coefficients of two-dimensional wavefront are computed from two one-dimensional difference wavefronts which are acquired by shearing interferometer. A recipe for data pre-processing is presented to solve information leakage resulting from large shear. This technique is applicable to situation where the shear amount is larger than one sampling interval, and can alleviate the limitation on the shear amount imposed by conventional algorithm. Investigation into the influences of shear amount and noise level on reconstruction accuracy is made.