Screening of singular points of vector field of phase gradient, localization of optical vortices and reconstruction of wavefront with screw dislocations

The algorithms for screening singular points of the phase gradient vector field are developed, where vector field components can be measured with a Shack-Hartmann wavefront sensor or shearing interferometer. Special attention is focused on the singular points that allow localization of optical vortices (wavefront dislocations). Determination of the coordinates and the topological vortex charges is of special importance in optical vortex interferometry, in operation of optical communication devices that encode information by means of optical vortices, and for reconstruction of phase distribution of optical beams that propagate in a medium with dislocations. On basis of numerical modeling, accuracy of the algorithm is verified, comparison with other algorithms executed, and its advantages and drawbacks are analyzed. Performance results are presented of the singular wavefront recovery algorithm, whose operating requirement is preliminary detection of optical vortex dislocations.