Topological charge parallel measurement method for optical vortices based on computer-generated holography

The generation, propagation, and application of optical vortices have been major researched topics in recent years. In this study, a parallel measurement approach is presented to analyze the topological charge of single and composite optical vortices with the help of a spatial light modulator. The topological charges of single and composite optical vortices are measured by observing the Gaussian point position of the diffracted field, which solves the difficult problem of measuring composite optical vortices and optical vortices with large topological charges. The presented method is feasible and has strong expansibility. More composite optical vortices can be measured easily by using different computer-generated holograms. When an optical vortex is measured correctly, it can present a Gaussian point, which retains the characteristics of the optical vortex. Therefore, this point will be important in optical vortex communication.