Broadband high-efficiency polarization-encoded meta-holograms based on 3-bit spin-decoupled reflective meta-atoms.

Metasurfaces are engineered planar surfaces consisting of arrays of resonators for tailoring the electromagnetic wavefronts in a desirable way. However, the spin-locked issue of the geometric metasurfaces hinders simultaneous manipulation of both spins. In this work, a spin-decoupled information metasurface composed of simple C-shaped resonators is proposed to realize two different information channels under the orthogonal circularly polarized (CP) incidences. Based on the encoded digit '0' or '1', the diffusion scattering or a holographic image could be realized under the CP excitation in a broadband frequency range from 9 to 12 GHz. As an illustrative example, a 3-bit polarization-encoded meta-hologram is designed, fabricated, and characterized. The measured results agree very well with the numerical results, which gives the proposed method great potential in numerous applications such as holographic displays and information processing.