Perfect optical vortex array for optical communication based on orbital angular momentum shift keying

We proposed a simple and efficient method to create a 2D perfect optical vortex (POV) array based on the Fourier shift theorem and a 2D POV array hexadecimal encoding/decoding method to realize high capacity data transmission. The encoding data sequence contains the position and topological charge information of each POV, which can be modulated by adding a phase shift factor to a specially designed hybrid phase-only grating. Based on the position and topological charge information, the 2D POV array can realize spatial division multiplexing and orbital angular momentum shift keying. The hexadecimal encoding/decoding method was investigated both theoretically and experimentally. The experimental results show that this method has potential applications in high capacity optical communications.