High-efficiency vectorial holography based on ultra-thin metasurfaces

Holography plays a crucial role in optics, yet traditional methods require complex setups and bulky devices, being unfavourable for optical integration.Although metasurface-based holograms can be ultracompact, holographic images generated by previously realized metadevices were mostly scalar ones, with a few vectorial holograms realized so far suffering from restrictions on efficiency, incident polarization, and resolution.We propose and experimentally demonstrate an efficient meta-platform to generate vectorial holographic images with high resolutions under arbitrary incident polarizations.Combining Gerchberg-Saxton algorithm and the wave-decomposition technique, we establish a generic strategy to retrieve the optical properties (e.g., reflection phases and polarization-conversion capabilities) of meta-atoms required to construct a metasurface for generating a predesigned vectorial holographic image under a predesigned incident polarization.We next design a series of high-efficiency and deep-subwavelength single-structure meta-atoms exhibiting tailored reflection phases and polarization-conversion capabilities governed by both structural resonances and the Pancharatnam-Berry effect, and experimentally characterize their optical scattering properties.We finally construct a series of ultra-thin metadevices with these meta-atoms and experimentally demonstrate that they can generate pre-designed vectorial holographic images under illuminations of circularly polarized light at 1064 nm.We provide a highly efficient and ultra-thin platform to generate predesigned vectorial holographic images under illuminations of light with arbitrary given polarization, which can inspire numerous future applications in on-chip photonics.