Data Processing of Phase-shifted Shearing Interferogram for Testing Aspheric Surfaces

摘要

Surface shape precision of optical aspheric surface is generally better than λ/4(λ = 0.6832 m). Interferometries are often used to test optical aspheric surfaces. Shearing Interferometry is one of these methods. In this paper, a method of data processing of a phase-shifted shearing inter-ferogram for testing optical aspheric surface is presented. Zernike polynomial functions are used to describe the wave front in this method. And to reduce computing error, Moore-Penroe inverse matrix is used. Computer simulations results show that the method is feasible and its precision is high enough.