Real-time phase step measurement using the volume enclosed by a surface algorithm in self-calibrating phase-shifting interferometry

This manuscript presents a simple, and very efficient method capable of measuring in real-time the phase steps from an interferogram varying with the time. Within a range (0, 2 pi) given by the phase steps of two fixed reference interferograms. The phase differences among the dynamic and reference interferograms are computed by an algorithm of type self-calibrating generalized phase-sifting interferometry based on geometric concept of volume enclosed by a surface. This proposal has the property to accept or reject the measured data, and its calibration process is very easy, which are very important advantages, so it is a very practical method. Theoretical model is described, verified with a numerical simulation, and applied to measure experimentally the phase steps in three optical tables with different conditions. (C) 2019 Elsevier Ltd. All rights reserved.