Asymmetric metasurfaces with high-$Q$ resonances governed by bound states in the continuum

TL;DR

This paper demonstrates that asymmetric metasurfaces can support high-Q resonances linked to bound states in the continuum, providing a theoretical framework for engineering advanced nanophotonic devices.

Contribution

It establishes a rigorous connection between bound states in the continuum and Fano resonances in asymmetric metasurfaces, offering a general theory for their design.

Findings

High-Q resonances are supported by asymmetric metasurfaces.

A direct link between bound states in the continuum and Fano resonances is proven.

A general theory for engineering these resonances is developed.

Abstract

We reveal that metasurfaces created by seemingly different lattices of (dielectric or metallic) meta-atoms with broken in-plane symmetry can support sharp high-$Q$ resonances that originate from the physics of bound states in the continuum. We prove rigorously a direct link between the bound states in the continuum and the Fano resonances, and develop a general theory of such metasurfaces, suggesting the way for smart engineering of resonances for many applications in nanophotonics and meta-optics.