Liquid‐Crystal‐Powered Metasurfaces for Electrically Continuous Brightness Modulation and Multidimensional Information Encryption and Storage

ABSTRACT

Metasurface‐based dynamic structural colors have been found wide applications in displays, anti‐counterfeiting and visual sensing due to their environmental friendliness, real‐time stimulus responsiveness, and wide color gamut. Liquid crystals (LCs), known for their optical anisotropy and sensitivity to external fields, provide an ideal platform for active metasurfaces. However, existing LC‐metasurface systems are mostly confined to discrete color modulation or binary ON‐OFF switching, limiting their capability for continuous brightness control. In this work, a cascaded structure combining a liquid crystal polarization rotator (LCPR) with silver nanogroove arrays (SNAs) to achieve continuous brightness modulation is proposed. By integrating the LC layer with a quarter‐wave plate, the polarization direction of incident light can be continuously rotated (0°–180°) under electrical control. Coupled with the optical rotation effect arising from the anisotropic plasmonic resonance of the SNAs, this enables on‐demand modulation of the output light intensity. As proof of concept, we experimentally demonstrate several applications, including single‐channel multi‐state information storage and switching, triple‐channel dynamic visual cryptography, and multi‐level optical anti‐counterfeiting QR codes. These results indicate broad application potential of the LCPR–SNA platform in high‐density, high‐security information encryption and storage, as well as optical anti‐counterfeiting.