Absolute angular displacement determination using a Mach-Zehnder interferometer

In this paper, a Mach-Zehnder interferometer that contains a polarizer, two identical lateral beam-splitters, and an analyzer is proposed for absolute angular displacement determinations. It divides the beam from a low-coherent light source into two interference beams whose interference signal is recorded by an image processing system. An angular displacement of one of the beam-splitters shifts the correlogram of the interference signal. The angular displacement can thus be examined by retrieving the position of the envelope peak of the correlogram. The theory of the interferometer is demonstrated. A setup constructed to realize the interferometer and the results of using this setup are then presented.