Self-calibrating five-frame algorithm for phase-shifting interferometry

Abstract

One of the main error sources for phase shifting interferometry is the linear phase shift error. This paper presents a self-calibrating phase-measuring algorithm that is free from errors produced by this error source. In the other words, the proposed algorithm is able to obtain an accurate phase at every pixel point in the interferograms over a wide range of equally spaced phase shifts. The algorithm requires the acquisition of five phase shifted interferograms. It resembles the well-known Carre' s algorithm, but with one extra frame. This algorithm, however, has considerable advantages over Cane' s algorithm.