Visualizing Circularly Polarized Long Afterglow for Information Security

Abstract

AbstractCreating security materials that carry distinct information with numerous optical characteristics enables enhanced anticounterfeiting levels to deter forgery ranging from currencies to pharmaceuticals. Circularly polarized long afterglow (CPLA) has attracted extensive attention in anticounterfeiting owing to its multiple and unusual optical properties (i.e., long afterglow and circular polarization), introducing intensity variation into the time dimension. However, constructing a visualized CPLA—meeting the requirements toward practical applications—is still a challenge. Here, a cementation‐coupling strategy is designed to combine chiral photonic membranes with phosphor films for building full‐colored CPLA architectures. The CPLA systems achieve desired performance with a largest afterglow dissymmetry value (gCPLA) of −0.67 and a longest visualization time (tvis) of 40 min simultaneously, satisfying practical demands for information security. As‐prepared CPLA materials are further patterned to work as optical labels in security fields. The resulting multidimensional variations in both time and intensity increase the complexity of information encryption, offering potentials for advanced security technologies.