In various areas of photonics, there is a tendency to move from elements of physical optics to elements of flat optics, primarily due to reducing dimensions of instruments and devices. Usually, spatial light modulators are used to quickly output flat phase elements. In this paper, the possibility of replacing the optical system with a computer-generated lens was investigated. The novelty of the work lies in a comparative analysis of point spread functions formed by an optical system and a computer-synthesized lens. Numerous experiments confirm the result.

Phase shifts of light in the orders of diffraction gratings for the interference sensor of linear displacements are considered. The use of a phase diffraction grating with given geometrical parameters of the surface relief makes it possible to stabilize the phase relationships in the optical signals and, as a result, in the final signals taken from the displacement sensor. Based on mathematical modeling data, technically feasible parameters of the surface relief of diffraction gratings are proposed to create the required phase shifts between the diffracted beams and quadrature modulation signals and to achieve the required measurement accuracy with nanometric resolution.