Visible-Frequency Dielectric Metasurfaces for Multiwavelength Achromatic and Highly Dispersive Holograms

TLDR

Dielectric metasurfaces composed of high‑index nanostructures enable highly efficient flat optical devices through tunable electromagnetic scattering and high transmission. The authors demonstrate visible‑frequency silicon metasurfaces built from three types of nanoblocks multiplexed into a subwavelength unit that can simultaneously manipulate red, green, and blue wavefronts. Full phase control for each color is achieved by independently rotating the corresponding nanoblocks to impose geometric phases, and the resulting achromatic, highly dispersive meta‑holograms are fabricated to showcase high‑resolution wavefront manipulation. The fabricated meta‑holograms confirm achromatic, highly dispersive performance and suggest the technique is suitable for practical holographic and flat achromatic devices.

Abstract

Dielectric metasurfaces built up with nanostructures of high refractive index represent a powerful platform for highly efficient flat optical devices due to their easy-tuning electromagnetic scattering properties and relatively high transmission efficiencies. Here we show visible-frequency silicon metasurfaces formed by three kinds of nanoblocks multiplexed in a subwavelength unit to constitute a metamolecule, which are capable of wavefront manipulation for red, green, and blue light simultaneously. Full phase control is achieved for each wavelength by independently changing the in-plane orientations of the corresponding nanoblocks to induce the required geometric phases. Achromatic and highly dispersive meta-holograms are fabricated to demonstrate the wavefront manipulation with high resolution. This technique could be viable for various practical holographic applications and flat achromatic devices.