All-Dielectric Structural Coloration Empowered by Bound States in the Continuum

TL;DR

This paper introduces an all-dielectric metasurface using bound states in the continuum to generate vivid, tunable structural colors across the visible spectrum with high efficiency and color purity.

Contribution

It presents a novel dielectric metasurface design leveraging BICs for high-quality, tunable structural coloration, overcoming previous limitations in color accuracy and brightness control.

Findings

Supports sharp resonances across the visible spectrum

Enables versatile control of brightness and hue

Achieves high color saturation and wide gamut

Abstract

The technological requirements of low-power and high-fidelity color displays have been instrumental in driving research into advanced coloration technologies. At the forefront of these developments is the implementation of dye-free coloration techniques, which overcome previous constraints related to insufficient resolution and color fading. In this context, resonant dielectric nanostructures have emerged as a promising paradigm, showing great potential for high efficiency, remarkably high color saturation, wide gamut palette, and realistic image reproduction. However, they still face limitations related to color accuracy, purity, and simultaneous brightness tunability. Here, we demonstrate an all-dielectric metasurface empowered by photonic bound states in the continuum (BICs), which supports sharp resonances throughout the visible spectral range, ideally suited for producing a wide range of structural colors. The metasurface design consists of titanium dioxide (TiO2) ellipses with carefully controlled sizes and geometrical asymmetry, allowing versatile and on-demand variation of the brightness and hue of the output colors, respectively.