posted on 2023-01-25, 13:57authored byChandan Sengupta, Kallol Bhattacharya
In this exploration, we present a compact and easy-to-set imaging system to analyze quantitatively macroscopic and microscopic transparent phase samples (TPS) using interferograms created by a radial shearing interferometer (RSI). The proposed set-up employs a wire grid polarizer (WGP) as a beam-splitting optical element in a triangular cyclic interferometer (TCI) configuration to render the two counter-propagating beams linearly polarized in orthogonal directions as they emerge from the interferometer. These beams are made to pass through the TPS in a counter direction. The focusing lens to image the sample is aligned in such a way that either a p-polarized beam illuminates the phase sample in such a way that the sample is in focus with respect to the focusing lens and the other polarization fixed in focus of the lens and for s-polarized beam illumination it is far apart from its focal length. So due to this polarization phase shifting (PPS) is implemented so as to generate a three-dimensional (3-D) phase pattern which is digitally captured in a charge-coupled device (CCD) camera to yield the sample phase. The proposed setup is robust, sufficiently tolerant to ambient vibrations, and shows encouraging experimental results using minimum optics.