Full Space Control of Meta-Holograms Utilizing a Bilayered Patterned Coding Metasurface

Meta-hologram constitutes one of the most promising technologies for holographic imaging. However, most studies in the field of meta-hologram focus on the full space wavefront tailoring generated by phase gradient from unit cells in multilayer dielectric cascaded structure. In this letter, a full space monolayer meta-hologram is designed, fabricated and measured, which provides two different information channels in the regions where electromagnetic waves are transmitted and reflected. The proposed coding meta-atom is composed of a cross-shaped patch structure and a slot formed by two merged rectangles, placed on the two sides of a dielectric substrate. By tuning geometrical parameters of the patch and slot structures, 1-bit phase and amplitude modulation can be individually achieved under different linear polarization of incident waves. As a proof-of-concept, a single-layered full space meta-hologram is numerically and experimentally demonstrated. Results show that the different hologram images in the transmission and reflection modes can be independently controlled at the same frequency by orthogonally linearly polarized waves. Due to easy fabrication and unprecedented miniaturization capability, the proposed full space coding meta-hologram extends the route to broad prospects for data storage, information processing, resource saving and other imaging applications.