Rotationally Tunable Two-Beam Interferometer with a Fixed Photosensitive Element. Part II. Interferometer Based on a Beam-Splitter Unit

Abstract

A tunable (in terms of the angle of convergence of intersecting light beams) two-beam interferometer with fixed mirrors and a fixed photosensitive element is considered. The photosensitive element is based on a symmetric beam-splitter unit where tuning of the interference pattern period is ensured by only one type of motion: interferometer rotation with respect to the motionless source of the collimated light beam. It is demonstrated that the period can be controlled in this way for convergence angles from 30 to 180° for beams with diameters of 10% or more of the beam-splitter unit length. In this region, the greatest width of the range of convergence angle tuning can exceed 40°, and the admissible beam diameter approaches 40% of the beam-splitter unit length. Comparisons with a similar interferometer based on a beam-splitter cube are performed, and possible areas of application of the considered interferometer are determined.