Translation-controlled beam-steering metasurfaces for optical wireless communications

Beam-steering devices play a vital role in the realm of optical wireless communication (OWC). However, conventional beam-steering technologies based on spatial light modulators, digital micro-mirror devices, gratings, and waveguides have limited performance with tradeoffs between multi-functionalities, high modulation speed, and compactness, which significantly curtail the potential applications of OWC. Herein, a translation-controlled beam-steering metasurface consisting of two metalens arrays is designed, which can achieve high modulation speed, versatile functionalities, and ultra-compactness. In our simulation, multiple functionalities, such as single-angular-mode switching and switching between single-angular-mode and dual-angular-mode have been realized by shifting one of the metalens arrays. Moreover, the dimension of the meta-device is only 200 μm × 200 μm. Our preliminary experimental results show that the switching speed can reach up to 6 KHz. The proposed metasurface circumvents the previous issues, providing a new design paradigm for high-performance OWC.