Graphene-metal based tunable radiative metasurface for information encryption and anticounterfeiting

Tunable thermal radiation metasurfaces have important application prospects in thermal management, energy utilization, thermal information processing and other fields. In this paper, the thermal radiation metasurface is combined with information coding and infrared imaging technology. Based on graphene-metal hybrid structure, 1-bit and 2-bit tunable radiation coding metasurface containing two and four types of pixel structures respectively are designed for infrared anticounterfeiting and information encryption. The emissivity of these pixel structures is adjustable and satisfies specific relationships according to different design schemes and channel requirements. The spatial distribution of infrared emission is controlled by the spatial arrangement of different pixel structures to carry patterns, characters or digital information. With globally controlling graphene and/or infrared wavelength selection, infrared images can be displayed and switched, and hidden information can only be extracted in specific channels. Compared with the static metasurface and 1-bit coding metasurface, 2-bit coding metasurface has higher security and flexibility. The graphene-based tunable radiative metasurface and its pixel coding and infrared image display scheme proposed in this paper provide a new idea for expanding optical information encryption methods, which has great application potential in dynamic information encryption, high-end anticounterfeiting, optical data storage and information authentication.