A Spin‐Encoded All‐Dielectric Metahologram for Visible Light

Abstract

Abstract Dielectric materials that are low‐loss in the visible spectrum provide a promising platform to realize the pragmatic features of metasurfaces. Here, all‐dielectric, highly efficient, spin‐encoded transmission‐type metaholograms (in the visible domain) are demonstrated by utilizing hydrogenated amorphous silicon (a‐Si:H). In comparison to previously reported visible metaholograms based on TiO 2 and other dielectric materials, all‐dielectric metasurfaces provide a cost‐effective more straightforwardly fabricated (aspect ratio 4.7), CMOS compatible, and comparably efficient solution in the visible domain. A unique way of utilizing polarization as an extra degree of freedom in the design to implement transmission‐type helicity‐encoded metaholograms is also proposed. The produced images exhibit high fidelity under both right and left circularly polarized illuminations. The proposed cost‐effective and CMOS‐compatible material and methods open up an avenue for on‐chip development of numerous new phenomena with high efficiency in the visible domain.