Tri-channel metasurface fusion of continuously varying gray levels for nanoprinting and holographic displays.

Metasurfaces are extensively utilized in nanoprinting and hologram fusion displays due to their superior wavefront shaping capabilities. However, the creation of continuously varying grayscale images based on conventional Malus's law necessitates the use of at least one polarizer for observation, which compromises the metasurface's integration. In this study, inspired by the Jacobi-Anger expansion, we propose a tri-channel metasurface to establish three independent information channels for simultaneous grayscale nanoprinting and polarization multiplexed holography. By meticulously designing the sizes and orientation angles of the nanostructures, the multifunctional metasurface can generate a grayscale nanoprinting image observable in the near-field without any polarization control, and simultaneously reconstruct two distinct holographic images in the far-field under varying incident light conditions. With its advantages of ultra-compactness, high information capacity, flexible design, and ease of observation, the proposed multifunctional and tri-channel metasurface holds significant promise for potential applications in three-dimensional stereoscopic displays, information multiplexing storage, and beyond.