Cascaded Rotating Metasurfaces for Dynamic Beam Steering

Beam steering devices are essential components in several applications, such as detection, LiDAR, and optical communication. However, traditional beam steering devices tend to be bulky or exhibit a limited steering angle. Cascaded metasurfaces exhibit strong capabilities for powerful dynamic light modulation. In this work, we propose and demonstrate a highly integrated beam steering device utilizing two cascaded, independently rotating metasurfaces. Through simple relative rotation, the output beam can be continuously and dynamically steered, generating pre‐designed trajectories that densely cover a wide angular space. We have numerically simulated and experimentally verified continuous beam steering of petal‐shaped scanning trajectory with discrete scanning technique. Furthermore, by integrating traditional gradient phase design with the Dammann grating profiles, we achieved a wider scanning range and a greater number of addressable beam positions. This technology is compact, and versatile to utilize in various fields, including but not limited to optical sensing, light detection and ranging (LiDAR), and free‐space optical communication.