All-Dielectric Nanostructured Metasurfaces with Ultrahigh Color Purity and Selectivity for Refractive Index Sensing Applications

In this study, two kinds of nanostructured metasurfaces are presented and compared to exhibit ultrahigh color purity and selectivity in the visible wavelength range. The proposed nanostructured metasurfaces are composed of all-dielectric materials, which are Si3N4 fabricated on quartz substrates to form one-dimensional (1D) and two-dimensional (2D) nanogratings (NGs). These nanostructured metasurfaces exhibit over 98 % reflection intensity with ultra-narrow bandwidths less than 20 nm to perform vivid red, green, and blue colors, implying the po-tentials in high-saturation display. Among nanostructured metasurfaces, 2D-NGs allow a wider range of incident angle than 1D-NGs and show polarization-independent characteristic owing to the symmetric arrangement in nanoscale in the incident plane. Furthermore, the numerical simulation results prove that 1D-NGs and 2D-NGs exhibit single-and dual-resonance when exposed on the ambient environment with different refractive in-dexes. Such excellent optical performances verify their potentials not only in high-resolution display but also in chemical sensing applications.

Automated summary

This study presents and compares two kinds of nanostructured metasurfaces for ultrahigh color purity and selectivity in the visible wavelength range. The nanostructured metasurfaces exhibit narrow bandwidths and high reflection intensity, making them suitable for high-saturation display and chemical sensing applications.