Full Space Manipulation of Meta-Hologram Utilizing 4-Bit Millimeter-Wave Metasurface

In this letter, a novel approach is proposed, where a 4-bit Janus metasurface operating in the millimeter wave band is combined with the Weighted Gerchberg-Saxton (WGS) algorithm for the recording and reconstruction of two distinct images. Through meticulous engineering the single-layer unit design, the 4-bit metasurface achieve independent and simultaneous amplitude and phase responses in two orthogonal information channels. Moreover, the effects of imaging are investigated under different amplitude and phase dispersion conditions. Comparative analysis also demonstrates several notable advantages of our work, in-cluding a low-profile design, dual-polarized multiplexing, and enhanced imaging efficiency.