Phase shifting interferometry using a coupled cyclic path interferometers

Abstract

In this research we implemented a two-step phase shifting system based on two cyclic-path coupled interferometers for slope measurements of transparent samples. The optical system generates two π-shifted interferograms, and the phase shift between interferograms is obtained by rotating a linear polarizer, generating four interferograms with relative π/2-phase shifts; this simplifies the number of phase steps necessary to retrieve the optical phase, since is only necessary perform a shift operating a linear polarizer. The optical phase was processed by a four-step algorithm. In order to present the capabilities of the system, results obtained for slope for transparent structures are presented.