Precise topographic manipulation in polyoxometalate/polymer enables multi-level optical authentication.

Abstract

Surface topographic manipulation plays a key role in advanced photonic devices. However, traditional azobenzene polymers or photoresists still face significant challenges in response speed and processing precision. Herein, we couple ultra-small polyoxometalate molecules with polyvinyl alcohol through hydrogen bonding to construct precision topographic manipulation with a detectable vertical modulation height down to 1 nm. The holographic relief gratings are obtained by photo-induced redox, local softening, and mass transfer, exhibiting a diffraction efficiency of up to 20% with a second-level response time. Utilizing multi-exposure, we achieve rapid fabrication of complex surface relief structures. Then, macroscopic physical patterns, dynamic structural colors, and 3D nested steps are integrated to construct a multiple "Holo-Lock". The photonics device achieves sequential authentication from intuitive naked-eye recognition to deep laser encryption, enhancing information security. This work paves a bright way to realize data storage, customizable micro/nanostructures, and advanced holographic display.