Bidirectional high-speed optical wireless communication with tunable large field of view assisted by liquid crystal metadevice

Beam-steered infrared (IR) light communication has gained tremendous attention as one of the solutions of congested wireless communication traffic. High performance active beam-steering devices play a crucial role in data allocation and exchange. Conventional beam-steering devices such as spatial light modulator (SLM) and micro-electrical mechanical system (MEMS) mirror and the current emerging nonmechanical beam-steering metasurface-based devices are challenging to realize a large tunable steering angle beyond several degrees, which significantly hinders the spatial application of optical wireless communications (OWC). Herein, an angle-magnified liquid crystal (LC) metadevice consisting of LC metasurfaces and a liquid crystal on silicon (LCoS) is proposed to realize active beam steering with a tunable large field of view (FOV). Based on the angle-magnified tunable LC metadevice, an intelligent bidirectional high-speed OWC system is experimentally demonstrated, achieving an actively enlarged FOV of 20° × 20°, with a data rate of 200 Gbps over the S/C/L band for both uplink and downlink transmission over a propagation distance of 1.5 m in free space. The proposed OWC system opens a new avenue for the future high performance wireless data transmission.