Interference Methods for the Structured Light Formation

This article describes an experimental study of a method for generating an optical vortex and its analysis in far-field diffraction using rays reflected from a combination of two retroreflectors or corner-cube reflectors (CCR) with a special interference phase-shifting coating, which are part of a polarization interferometer. With the correct location of the CCRs relative to each other, a second-order optical vortex is formed. The main goal of the experimental studies is to confirm the previously predicted theoretical possibility of obtaining an optical vortex in the near and far diffraction zones, as well as conducting their visual analysis. Schemes have been created that make it possible to generate second-order optical vortices in the near and far diffraction zones. A shearing interferometer was used to analyze the resulting patterns. The article presents diagrams of installations for the formation of an optical vortex and its analysis. The results show that the phase and polarization distributions of the resulting patterns are consistent with theoretical studies. Currently, there remains an increased interest in the study of optical vortices and methods for their generation. They are increasingly being used for micromanipulation and data transmission purposes. The proposed generation method, despite a number of limitations, can be useful in a number of problems — in particular, when it is necessary to quickly turn on and off the vortex, when using non-monochromatic light, and also when manipulating entangled photons.