Full field phase imaging using a harmonically matched diffraction grating pair based homodyne quadrature interferometer

Abstract

In this letter, the authors present a novel quadrature interferometry method based on the use of a harmonically matched shallow grating pair. Unlike a simple beam splitter or single shallow grating, the grating pair can confer a nontrivial interference phase shift (other than 0° or 180°) between the output ports of the interferometer. Using the grating pair as the beam splitter/combiner, the authors implement a homodyne quadrature full field phase interferometer and demonstrate the system’s capability to acquire phase and amplitude images.