Metasurface Hologram for Multi-Image Hiding and Seeking

Image encoding and decoding are significant for information security, authenticity verification, and anticounterfeiting. We propose and demonstrate a polarization multiplexed metasurface for multi-image hiding and seeking in the terahertz band. The designed metasurface is composed of rod slot antennas and C-shaped slot antennas operating for both linear and circular polarizations. Different hidden images are revealed by controlling the polarization states of the incident and detection light. Three channels for object image encoding are demonstrated, indicating that this approach can increase the degree of freedom for optical image hiding and verification. This work may open an alternative avenue for polarization-controlled metasurface design, product identification, optical image encoding, and optical information security.