Polarization-Independent and High-Efficiency Dielectric Metasurfaces Spanning 600-800 nm Wavelengths

TL;DR

This paper presents experimentally demonstrated dielectric metasurfaces that are polarization-independent and highly efficient across a broad visible spectrum, enabling advanced flat optical devices.

Contribution

First experimental realization of polarization-independent, high-efficiency dielectric metasurfaces spanning 600-800 nm using multi-fold symmetric silicon nanopillars.

Findings

Diffraction efficiencies up to 93% at 670 nm

Efficiency exceeds 75% across 600-800 nm for orthogonal polarizations

Potential to replace traditional optical components

Abstract

Artificial metasurfaces are capable of completely manipulating the phase, amplitude, and polarization of light with high spatial resolutions. The emerging design based on high-index and low-loss dielectrics has led to the realization of novel metasurfaces with high transmissions, but these devices usually operate at the limited bandwidth, and are sensitive to the incident polarization. Here, for the first time we report experimentally the polarization-independent and high-efficiency dielectric metasurfaces spanning the visible wavelengths about 200 nm, which are of importance for novel flat optical devices operating over a broad spectrum. The diffraction efficiencies of the gradient metasurfaces consisting of the multi-fold symmetric nano-crystalline silicon nanopillars are up to 93% at 670 nm, and exceed 75% at the wavelengths from 600 to 800 nm for the two orthogonally polarized incidences. These dielectric metasurfaces hold great potential to replace prisms, lenses and other conventional optical elements.