An analysis of an optical vortices interferometer with focused beam

In recent years a lot of effort was put into testing and improving the idea of a three-beam interferometer known as an optical vortices interferometer (OVI). Devices based on file idea of the OVI allow measuring small rotation angles and small shifts with a superb resolution Unfortunately, there are still many problems that have to be solved before an OVI-based device can go into production. In this paper, theoretical calculations and experimental results of using another type of OVI, OVI with focused beam, are presented. The results of measuring small displacements and small rotation angles of reflecting, areas are also shown.