Generation of Collinear Superimposed Orbital Angular Momentum Modes Using a Phase-only Grating

In this paper, an Orbital Angular Momentum (OAM) generation method based on Adapted Mutation Particle Swarm Optimization (AM-PSO) algorithm is proposed. Based on the traditional iterative algorithm, the AM-PSO algorithm simultaneously generates multiple OAM modes with higher iterative efficiency. The simulation results show that 20 evenly spaced OAM modes are generated through a phase-only grating with high diffraction efficiency and low relative root-mean-square error (R-RMSE). Moreover, the relative power distribution can be easily manipulated by adjusting the weight coefficients of OAM modes.