Currently, uniaxial crystalline lenses become more widely used in laser technology and coherent optics. There are several types of crystalline lenses consisting of two lenses of a uniaxial crystal, which differ in the orientation of optical axes. These lenses are used in the mode of normal light incidence on the input face and carry out a shift between the wave fronts of ordinary and extraordinary beams at the output. The superposition of these waves at the output of crystalline lenses results in the occurrence of an interference pattern that can be used for a variety of purposes in laser polarized interferometers. A theory of the optical properties of crystals has been developed, according to which the path of ordinary and extraordinary beams in crystalline lenses can be calculated for normal incidence of light on the input face of a crystalline lens. Crystalline lenses are used for releasing laser radiation in various laser measurement devices, obtaining a constant shift between the wave fronts of these beams, spatial encoding and decoding, spatial multiplying of optical signals and creating a controlled spatial filter. Many accurate measurements, the role of which is rapidly increasing in modern science and technology, are carried out by interference methods. The scope of application of interference devices has expanded through the creation of lasers and the development of electronics.

interference, crystal coherence, lens, radiation laser, focus, raster, input, ordinary, unusual.