Interactive Nanophotonic Platforms for Multimodal Information Storage and Security

Multimodal photonic information systems are redefining the landscape of data storage and encryption by harnessing a diverse range of optical channels and stimuli-responsive materials. Within these interactive photonic platforms, information can be encoded not only through spatial patterns but also across wavelength (color), intensity, polarization, phase, and temporal domains, significantly enhancing storage density and security. This review provides a comprehensive overview of the current state of multimodal photonic encryption and data storage with particular emphasis on the chemistry of advanced luminescent and nanostructured materials and the device physics underlying their unique optical behaviors. We delve into fundamental photonic encoding strategies, ranging from structural color and metasurface holography to fluorescence/phosphorescence and electroluminescence, and discuss how multiple emission pathways can be coupled within single platforms. Various external stimuli (optical, electrical, magnetic, thermal, mechanical, and chemical) used to activate or unlock photonic signals are examined, highlighting designs in which specific stimuli act as secure cryptographic keys. We then review strategies for engineering multimodal photonic platforms, including the integration of orthogonal emission channels, spatial and temporal multiplexing, and device architectures (thin films, fibers, metasurfaces, and multilayers) that support complex hierarchical encoding. Mechanisms of photonic encryption are discussed, distinguishing static from dynamic approaches and detailing how stimuli-responsive modulation, time-gated luminescence lifetimes, and logical multistep unlocking schemes enhance security beyond conventional optical tags. Finally, application-oriented sections illustrate how these advances are being translated into real-world security architectures, ranging from anticounterfeiting labels, encrypted displays, and wearables to secure QR codes and optical memory elements for neuromorphic computing.