Information encoding with a segmented vortex beam

In this paper we propose an information encoding method based on a segmented vortex beam. The segmented vortex beam with a single uniform-intensity ring and a combination of multiple topological charges is designed for information encoding. The radius of the beam can be designed to be arbitrary, with multiple orbital angular momentum states superimposed along the ring. We encoded the information into the segmented vortex beam in the transmitting unit for information transmission. Due to the segmented phase structure of the beam, information can be encoded in each segment, and the information capacity is significantly increased. Additionally, enormous combinations of encoded information in the beam can greatly enhance the security of the encoded information. This proposed method has great potential in free-space optical communication.