Simple laser interferometer for the space optical systems measurements

A new small and simple laser interferometer is discussed. The interferometer consists of a laser, small mirror sphere (mirror ball), optics to be tested, a small flat mirror, and a receiver of Twyman-Green fringes. The interferometer works of the following way: part of a beam from the laser reflects from the mirror ball, forming the analyzer beam reflecting by the optical system to be tested. Then analyzer beam is directed to the receiver. Part of the laser beam reflects from the small flat mirror directing the light to the mirror ball, forming the reference beam on the receiver. The reference beam is recombined with the analyzer beam on the receiver to produce the system of Twyman-Green fringes. The interferometer is very small, simple and lightweight, that is why it is especially recommended for testing optics of the Space telescopes in the orbit, EUV or IR optical testing, and so on.