Dynamic Augmented Reality Display by Layer‐Folded Metasurface via Electrical‐Driven Liquid Crystal

Abstract Heading toward the next‐generation versatile meta‐devices and meta‐systems with increasing complexity, it inevitably demands the cascading and coupling between multi‐layer metasurfaces to create new design space for meta‐optics. However, the accurate requirement for multilayer alignment at the nanoscale is significantly challenging due to the actual fabrication limitation, thus hindering the state‐of‐the‐art meta‐optics device integration and its practical application. Herein, a dynamic meta‐system for augmented reality (AR) holographic display functionality based on a layer‐folded metasurface integrated with an electrical‐driven liquid crystal (LC) platform is originally proposed and realized. By ingeniously folding the optical path between meta‐device vertical space, a beam‐steering metasurface in parallel with the other two holographic metasurfaces placed on a single surface is successfully cascaded. Such a layer‐folded scheme enjoys single‐time lithography processing for multi‐patterning with nanoscale alignment accuracy and avoids any vertical alignment issue. Furthermore, by combining with an electrical‐driven LC tuning scheme, the integrated meta‐system could actively switch independent‐encoded holographic images in real‐time floating in the actual‐world scene. Overall, it is envisioned that such a compact dynamic meta‐system suggests a feasible route for dynamic tunable wearable AR displays, intelligent dynamic displays, multi‐functional devices, etc.