Tunable Optical Metamaterial Enables Steganography, Rewriting, and Multilevel Information Storage.

In the realm of secure information storage, optical encryption has emerged as a vital technique, particularly with the miniaturization of encryption devices. However, many existing systems lack the necessary reconfigurability and dynamic functionality. This study presents a novel approach through the development of dynamic optical-to-chemical energy conversion metamaterials, which enable enhanced steganography and multilevel information storage. We introduce a micro-dynamic multiple encryption device that leverages programmable optical properties in coumarin-based metamaterials, achieved through a direct laser writing grayscale gradient strategy. This methodology allows for the dynamic regulation of photoluminescent characteristics and cross-linking networks, facilitating innovative steganographic techniques under varying light conditions. The integration of a multi-optical field control system enables real-time adjustments to the material's properties, enhancing the device's reconfigurability and storage capabilities. Our findings underscore the potential of these metamaterials in advancing the field of microscale optical encryption, paving the way for future applications in dynamic storage and information security.