Enabling Optical Steganography, Data Storage, and Encryption with Plasmonic Colors

Plasmonic color generation utilizing ultrathin metasurfaces as well metallic nanoparticles holds a great promise for wide range of applications including displays, data storage, and information encryption due to its high spatial resolution mechanical/chemical stability. Most the recently demonstrated systems generate static colors; however, more advanced such storage require fast flexible means tune plasmonic colors, while keeping them vibrant stable. Here, surface-relief aluminum metasurface that reflects polarization-tunable colors is designed experimentally demonstrated. Excitation localized surface plasmons encodes discrete combinations incident reflected polarized light into diverse colors. A single unit, namely nanopixel, stores multiple-bit in orientation constituent nanoantennae, which conveniently retrived by inspecting sequence with two linear polarizers. Owing broad variability metasurface, proposed encoding approach strong rapid parallel readout high-density optical data. The method also enables robust dynamic kaleidoscopic images without “cross-talk” effect. opens up new route steganography, parallel-access encryption.