| 초록 |
Metasurfaces, 2D metamaterials, is capable of expressing colors by its nanostructure. This structural coloration have been of great interests, requiring a broad color spectrum as well as tunable functionality for real-life application. Here, we would like to introduce our cryptographic nanoprints by metasurface coloration. Our hydrogenated amorphous silicon metasurfaces achieve diverse colours due to its high refractive index and near-zero extinction coefficient. We deploy nanocuboid-antennas which is designed based on Kerker’s condition for tunable functionality. We demonstrate cryptographic nanoprints that contain encrypted optical information under unpolarized light, where the hidden information can be decoded under polarized light of a specific angle. This dual optical data storage enables doubly-secured QR codes as optical cryptography. We success to scan those QR codes with smartphone scanner, connecting nano planar optics (metasurface) with smartphone technology (IoT). |
