Temperature-assisted terahertz reconfigurable metasurface for multi-polarization holographic display and encryption

•Based on the phase change property of VO2, the designed metasurface realizes temperature-assisted and polarization-controlled multi-channel holograms.•The designed metasurface exhibits excellent imaging quality and broadband characteristic, which are advantageous for integration into optical devices.•The proposed holographic encryption strategy provides the unparalleled security and has great potential for application in the field of information security. Metasurface holography has garnered considerable attention due to its advantages of wavefront manipulation capability and small pixel size. However, most existing works utilize static metasurfaces to realize holographic imaging, lacking the ability to dynamically manipulate holograms. This work utilizes phase change material-vanadium dioxide (VO2) in simulation to enable active modulation of vector holography. The encodings of well-designed meta-atoms can be reconfigurable through VO2 phase change, which is used to generate multi-polarization holograms. As a proof-of-concept, a 0° linearly polarized wave is vertically incident on the designed metasurface. When VO2 is in its metallic state, the reflected 0° and 90° linearly polarized waves exhibit holograms of symbols “+” and “−” respectively. When VO2 is in its insulating state, the reflected 45° and 135° linearly polarized waves display holograms of symbols “×” and “÷” respectively. Furthermore, a holographic encryption strategy is introduced, requiring concurrent possession of a customized key and the metasurface for the retrieval of the encrypted information. Our work presents a novel approach for dynamic display of holograms, offering significant potential for applications in holographic display and encryption.