A new method for laser beam phase measurement by using the shear interferometer

摘要

A new method, named FSI (Fourier Shear Interferometry), is suggested to calculate the phase derivative by Fourier transform of the lateral shear fringes. After filtering intensity spectrum A_F~2(f_x,f_y) in the spectrum of the shear fringes, the cross term of the fringe's intensity, i.e., A(x, y)A(x + s, y)exp[iΔ_xφ(x,y)], is obtained by the reverse Fourier transform, and then Δφ(x, y) can be easily obtained if only |Δφ(x,y)| ≤ π . The numerical simulation results demonstrate feasibility and accuracy of the suggested method.