Aluminum Plasmonic Multicolor Meta-Hologram

TLDR

The study presents a phase‑modulated multicolor meta‑hologram capable of producing polarization‑dependent images in red, green, and blue. The hologram consists of aluminum nanorods patterned on a 30 nm SiO₂ spacer over a 130 nm aluminum mirror, arranged in a 2‑D pixel array whose surface plasmon resonances in red, green, and blue enable polarization‑dependent image projection with wavelength‑dependent diffraction angles. The design yields narrow‑band resonances enabling multicolor holography, and by tuning nanorod size the image color can be continuously varied across the visible spectrum.

Abstract

We report a phase-modulated multicolor meta-hologram (MCMH) that is polarization-dependent and capable of producing images in three primary colors. The MCMH structure is made of aluminum nanorods that are arranged in a two-dimensional array of pixels with surface plasmon resonances in red, green, and blue. The aluminum nanorod array is patterned on a 30 nm thick SiO2 spacer layer sputtered on top of a 130 nm thick aluminum mirror. With proper design of the structure, we obtain resonances of narrow bandwidths to allow for implementation of the multicolor scheme. Taking into account of the wavelength dependence of the diffraction angle, we can project images to specific locations with predetermined size and order. With tuning of aluminum nanorod size, we demonstrate that the image color can be continuously varied across the visible spectrum.