Quantitative phase analysis of transparent phase objects in a radial shearing interferometer incorporating a wire-grid polarizer

In this exploration, we present a compact and easy-to-set imaging system to analyze the quantitative phase information of macroscopic and microscopic transparent phase samples using a radial shearing interferometric design. The proposed setup introduces a wire-grid polarizer as a beam-splitting optical element in a triangular cyclic configuration to render the two counter-propagating beams linearly polarized in orthogonal directions. These beams are made to pass through the samples in a counter direction. The focusing lens to image the sample is aligned in such a way that either the p-polarized beam illuminates the phase sample in a focused position concerning the imaging lens position and the remaining s-polarized beam is far apart from its focal length or vice versa. Hence, polarization phase shifting is implemented to generate a three-dimensional phase pattern, which is digitally captured in a charge-coupled device camera to yield the sample phase. The proposed setup is robust and sufficiently tolerant to ambient vibrations and shows encouraging experimental results using the minimum optics.