Two-level optical encryption platform via an electrically driven liquid-crystal-integrated tri-channel metasurface.

Metasurface-based optical encryption techniques have garnered significant attention due to their ultracompact nature and ability to support multichannel optical responses. Here, we present a liquid-crystal (LC)-integrated metasurface that enables polarized-encrypted amplitude and phase multiplexing. This approach allows for simultaneously realizing trifold displays of both meta-holography and meta-nanoprinting. By combining propagation and geometric phase modulation, we meticulously screen the unit cells of the metasurface, establishing a comprehensive structural dictionary. As a proof-of-concept, we developed an electrically driven advanced optical encryption platform that boasts multifunctional channels and two-level encryption capabilities. This study paves the way for advanced optical encryption and identification techniques.