Programmable luminescent platform based on carbon quantum dots enables wavelength‐multiplexed optical data storage and encryption

The ever‐growing global data volume demands storage technologies with high capacity and security. Optical data storage presents a promising alternative to electronic and magnetic systems, yet its development is hindered by the lack of media that combine optical writability, high capacity, facile processability, and robust stability. Here, we report a carbon‐quantum‐dots (CQDs)‐based programmable luminescent platform for multidimensional optical information encryption and high‐capacity data storage by leveraging wavelength‐division multiplexing. Through synergistic exciton localization engineering of the graphitic core and surface functional groups, we precisely tailored multiple emissive centers within CQDs, achieving seven distinct fluorescence colors with excellent spectral tunability in both solution and solid states. This color multiplexing enables the construction of encryption patterns that concealed under both ambient light and ultraviolet excitation, which are only decipherable through specific optical filters, significantly elevating information security. Furthermore, we demonstrate a prototype tri‐layer optical disk, where data written via laser ablation on different CQD layers are retrieved in parallel through selective filtering, tripling the areal storage density compared to conventional hard disks. Our strategy, which integrates a fundamental exciton manipulation model with a parallel readout architecture, circumvents the need for complex spectroscopic detection and opens a versatile pathway toward next‐generation high‐density, high‐security, and portable data storage systems.