High-Efficiency Near-Infrared Beam Steering Enabled by a CMOS-Driven Liquid-Crystal Metasurface.

Abstract

Dynamic control of light, particularly beam steering, is essential for applications, such as optical communications, LiDAR, and advanced imaging. Optical metasurfaces composed of subwavelength nanostructures provide a powerful platform for ultrathin wavefront engineering. Here, we demonstrate a compact near-infrared beam-steering device based on CMOS-driven liquid-crystal metasurfaces. From the combination of the Mie resonances of silicon nanoantennas with Fabry-Perot cavity-induced phase accumulation, the device enables continuous phase modulation approaching 2π. Enabled by a CMOS backplane with independently addressable electrodes, the device achieves an ultracompact pixel pitch of 0.8 μm and integrates 2500 independently addressable one-dimensional (1D) electrode arrays. As a result, electrically controlled 1D beam steering with a field of view of up to 24° is achieved. The diffraction efficiency reaches ∼40% at small angles and remains above 18% at the maximum deflection. This scalable, CMOS-compatible architecture provides a promising route toward next-generation spatial light modulators for near-infrared photonics.