Fringe scanning point diffraction interferometer by polarization

摘要

A polarization fringe scanning digital interferometer includes an encoder for performing a phase polarization encoding on the wavefront coming from the optical component under test as it passes through the encoder. The encoded wavefront then passes through an analyzer into a video camera to produce electrical signals representing the interference pattern. The encoder includes in sequence, a polarizer having an adjustable polarization axis, a polarization film providing a polarization pinhole through the film and a quarter wave plate that preferably is a Fresnel plate.