Polarization-multiplexed disorder-encoded metasurface for multi-channel optical encryption

In recent years, the use of speckle patterns has gained increasing attention in the context of optical encryption. Conventional scattering media (CSM), due to their fixed functionality, are mostly limited to single-channel encryption, which restricts further improvements in system security. Metasurfaces, as two-dimensional devices capable of flexibly manipulating optical parameters, provide an ideal platform for achieving multiplexing functionality. Building on this foundation, we propose a polarization-multiplexed disorder-encoded metasurface (DEM) for multi-channel optical encryption. Serving as a physical key, the DEM not only enables dual-layer encryption of plaintext through cascading with quick response (QR) codes but also provides the encryption system with six independent polarization channels. The encryption capability of the DEM-based system has been verified through security attack analysis. The proposed DEM effectively expands the number of channels and enhances the data capacity of the encryption system, thereby significantly improving security and attack resilience, demonstrating promising potential for practical applications.