Two methods to determination topological charge in regular net of optical vortices

摘要

A regular net of optical vortices generated by three plane waves interference allows for a new kind of interferometer -Optical Vortex Interferometer. The precision of that kind of interferometer depends on a localization accuracy and phase reconstruction. One problem is the unique phase reconstruction. Interference of three waves can generate two identical interferograms with opposite topological charge of vortices, so information from three waves interferogram is not enough to the unique phase reconstruction. First method of topological charge determination requires one interferogram of two waves analyzed in an experiment and knowledge about a direction of laser beams. Second method is based on analysing interferogram with the fourth wave added.