Rotation-Driven Bidirectional Asymmetric Reconfigurable Holography Based on Spatially Cascaded Phase-Only Metasurfaces

As a new platform for electromagnetic wave modulation, the metasurfaces have demonstrated unprecedented capabilities in wireless communications, information encryption, and holographic displays. Multi-functional metasurfaces dramatically increase the ability of metasurfaces to process complex information. Here, by introducing directional degrees of freedom (DoFs), we design a holographic meta-device consisting of dual-layer spatially cascaded phase-only metasurface with bidirectional asymmetry display. The phase distributions of the dual-layer metasurfaces are optimized through reverse design according to preset targets. In addition, the multiplexing capabilities can be further expanded via the rotation multiplexing scheme. As a proof of concept, a bidirectional asymmetric holography meta-device is demonstrated in the microwave region. The proposed method may provide a new paradigm for asymmetric data burning in communications, large-capacity holographic display, and information encryption.