Metasurface Hologram for Multi-Image Hiding and Seeking

Abstract

Here a composed metasurface is designed for multi-image hiding and seeking in the terahertz band, based on polarization multiplexing. Manipulation of linear and circular polarization states simultaneously is demonstrated, using a combination of rod and C-shaped slot antennas. Furthermore, there is interference between the waves from the two types of antennas, since the linear and circular bases are not orthogonal, leading to the unique properties of the designed device. This work may show a fresh avenue for optical image encoding and optical information security.