Metasurface-Based High-Speed Photonic THz OAM Communication System

The terahertz (THz) and orbital angular momentum (OAM) technologies have become increasingly prominent since they can provide broad bandwidth and large amounts of multiplexing channels. In this paper, a high-speed communication system is proposed and demonstrated by employing photonics-aided THz signal generation and metasurface-based OAM multiplexing techniques. To take advantage of the large bandwidth in the THz band and reduce the complexity of the multiplexing device, the wideband unit operating at 100 GHz and the multiplexed metasurface are designed. After the performance is verified by both simulations and experiments, the generated OAM beams are used as multiplexing channels to transmit the communication signals with 16-ary quadrature amplitude modulation (16-QAM) modulation format, and a data rate of up to 48 Gbit/s is achieved. This work indicates that the metasurface can seamlessly bridge the OAM multiplexing and photonics-aided THz system, and is expected to pave the way towards the evolution of next-generation large-capacity wireless communication.