Gradient‐Momentum Engineering in Metasurface for Continuous and Asymmetric Beam Steering

ABSTRACT Dynamic beam steering is a key functionality in advanced optical systems such as LiDAR, free‐space communication, and machine vision. However, achieving compact, highly efficient, and high‐resolution beam steering in a compact transmissive platform remains challenging. Here, we present a transmissive metasurface engineered with spatially continuous and independently tunable in‐plane momentum gradients that enable continuous and asymmetric 2D beam steering. By laterally shifting the incident beam across the metasurface, continuous modulation of the output angle is realized, with experimentally measured steering ranges reaching 100° horizontally and 70° vertically. The metasurface design avoids reliance on high‐order diffraction, maintaining high theoretical efficiency exceeding 96% across the entire field of illumination. Experimental results confirm smooth angular progression with an average angular resolution of ∼0.4° and an averaged deflection efficiency of 58.1%. Furthermore, we demonstrate that the angular resolution and beam trajectory can be flexibly engineered by modifying the spatial gradient profile, allowing trade‐offs between resolution and coverage. The proposed meta‐optics platform offers a scalable and integration‐friendly solution for next‐generation nanophotonic beam steering, with significant potential for compact LiDAR, chip‐scale optical communication, and 3D sensing applications.