Chain of optical vortices synthesized by a Gaussian beam and the double-phase-ramp converter

Abstract

A full theoretical and experimental analysis of the chain of phase singularities generated when a Gaussian beam passes a double-phase-ramp converter is presented. The overall output beam structure includes a system of interrelated optical vortices (OVs) whose trajectories form a three-dimensional singular skeleton that can be applied for the trapping and guiding of microparticles. The internal structure of each individual phase singularity is characterized by the OV topological charge and by the morphology parameters of equal intensity ellipses in the OV-core area: ellipticity (minor-to-major axes ratio) and the inclination angle. The morphology parameters’ evolution is shown to be valuable for the metrology applications.