Transmission-reflection-integrated metasurface for full-space, six-channel, and polarization-multiplexed holography

This paper presents a transmission-reflection-integrated metasurface (TRIM) that enables six fully independent holographic channels across the entire spatial domain, enabled by polarization multiplexing in one transmission and two reflection pathways. The metasurface architecture combines orthogonal receiving-transmitting elements for efficient forward transmission with rotatable dual crossbars embedded in an inter-ground plane for bidirectional reflection. This hybrid configuration ensures channel independence through structural anisotropy, frequency selectivity, and ground-plane shielding, effectively suppressing inter-channel crosstalk. Each channel achieves high transmission or reflection efficiency (above 0.9) together with complete 2π phase modulation. Holographic reconstructions were achieved through design and analysis based on the Rayleigh-Sommerfeld (RS) diffraction theory in combination with the Gerchberg-Saxton (GS) algorithm. As a proof of concept, full-space, six-channel, and polarization-multiplexed holography with the simultaneous reconstruction of three distinct holograms-including vector letters, anisotropic numbers, and spin-decoupled patterns are experimentally demonstrated. The proposed TRIM offers a compact and versatile platform for high-capacity holography, advanced optical information processing, and multifunctional meta-optics.