Demonstration of Multiple Access FSO Communication System Based on Silicon Optical Phased Array

The silicon photonic optical phased array (OPA) has attracted enormous interest in free-space optical communication (FSO) owing to its high integration and agile beam steering. However, existing studies have only used its ability for fast beam switching to achieve point-to-multipoint communication, which results in link disconnection and time waste during the switching process. To address this problem, we make full use of the light field manipulation capabilities of Si-OPA to generate beams with multiple main lobes pointing to different targets at the same time, and combine code division multiple access (CDMA) to achieve uninterrupted point-to-multipoint communication. Through detailed data analysis, it is experimentally demonstrated that the proposed method has improved the communication efficiency by 24.576% compared with the previous beam-switching solution. This method provides a new application idea for Si-OPA in FSO communication.