High-Speed Duplex Free Space Optical Communication System Assisted by a Wide-Field-of-View Metalens

Free space optical communication (FSO) has gained significantattentiondue to the growing demand for a high information capacity. For FSObetween multiple or moving targets, a receiver with a wide angle ofacquisition capability is necessary. Traditionally, gimbals and faststeering mirrors have been used, but they are often difficult to makeboth compact and wide-angle. Here, a novel duplex FSO system is demonstrated,which utilizes a highly compact fiber coupling metalens to receiveand transmit signals in a large field of view up to 80 & DEG;. Highcoupling efficiency up to 48.8% at a wavelength of 1550 nm is experimentallyachieved. The small coupling loss enables the user to modulate anddirect the downstream power from the base station back along the samepath, saving energy and leaving only one source in the FSO system.The low bit error rate and the open and clear eye diagram resultsvalidate the excellent downlink/uplink communication performance ofa 10 Gbps FSO system empowered by the metalens. The system exhibitsa large field of view, high data rate, compact size, and low powerconsumption, which meets the size, weight, and power requirement ofsmart devices.