Vector mode division multiplexing in terahertz wireless link enabled by multifunction metasurfaces
Wanying Liu, Xiaohan Jiang, Kesen Ding, Jinlong You, Jianqiang Gu, Quan Xu, Lan Wang, Luyang Wang, Chunyang Bi, Yangfan Gu, Jing Zhang, Sen Gong, Jiaguang Han, Yaxin Zhang, Weili Zhang
Abstract
Terahertz (THz) wireless links have attracted significant attention due to their pivotal role in next-generation communication systems. Multiplexing is one of the key techniques used to expand channel capacity for high-speed data transmission in point-to-point wireless communication. Using a pair of multifunction metasurfaces, we construct mode division multiplexing (MDM) in THz wireless link with cylindrical vector beams (CVBs) as orthogonal channels. The proposed metasurfaces integrate the functions of CVB generation and vector mode multiplexing, greatly simplifying MDM links. The simulated and measured results show that the multiplexer/demultiplexers are broadband in the frequency range of concern (from 0.36 to 0.44 THz) and compatible with frequency-division-multiplexing and polarization-division-multiplexing. Importantly, we experimentally accomplished a two-channel MDM in a direct modulation THz communication system at 0.36 THz in which the maximum modulation speed is 5 GHz (isolation>20dB). This study will lay the groundwork for CVB-based multidimensional multiplexing in the THz spectrum, potentially enhancing high-capacity THz communication.