Highest efficiency grayscale all-dielectric meta-holograms

Abstract

Metasurfaces are ultra-thin patterned structures that emerged recently as planar metadevices [1] capable of reshaping and controlling incident light. Many designs and functionalities of metasurfaces suggested so far, are based largely on plasmonic planar structures, however most of these metasurfaces demonstrate low efficiencies in transmission due to losses in their metallic components. In contrast, all-dielectric resonant nanophotonic structures [2] avoid absorption losses, and can drastically enhance the overall efficiency [3-5], especially in the transmission regime. Recently we have seen a number of demonstrations of all-dielectric metasurfaces with ever-increasing transmission efficiency in both near infrared and visible spectral range. This makes dielectric metasurfaces a promising novel platform for flat optical devices such as waveplates, Q-plates, lenses, and holograms.