Phase-only transmissive spatial light modulator based on tunable dielectric metasurface

Dynamic metasurfaces Nanostructured metasurfaces can function as many passive optical elements. Now, S.-Q. Li et al. demonstrate that metasurfaces can be combined with liquid crystals to provide active control over light beams. With a view toward developing near-eye augmented reality display technology, they combined a dielectric metasurface with a liquid crystal layer to produce a tiny spatial light modulator. The results present a path for the development of dynamic metasurfaces as a platform for miniaturized optical technology with advanced time-dependent functionality. Science, this issue p. 1087 Combining metasurfaces with liquid crystals produces a tiny spatial light modulator. Rapidly developing augmented reality, solid-state light detection and ranging (LIDAR), and holographic display technologies require spatial light modulators (SLMs) with high resolution and viewing angle to satisfy increasing customer demands. Performance of currently available SLMs is limited by their large pixel sizes on the order of several micrometers. Here, we propose a concept of tunable dielectric metasurfaces modulated by liquid crystal, which can provide abrupt phase change, thus enabling pixel-size miniaturization. We present a metasurface-based transmissive SLM, configured to generate active beam steering with >35% efficiency and a large beam deflection angle of 11°. The high resolution and steering angle obtained provide opportunities to develop the next generation of LIDAR and display technologies.