Multiple Bound States in the Continuum: Towards Intense Terahertz Matter Interaction

TL;DR

This paper demonstrates how metasurfaces can generate multiple bound states in the continuum (BICs), enabling enhanced and tunable light-matter interactions for applications like sensing and photonics.

Contribution

It introduces a method to control multiple BICs using metasurfaces with asymmetric split resonant rings, expanding beyond single resonance limitations.

Findings

Multiple free-control BIC resonances achieved

Enhanced sensitivity in lactose detection demonstrated

Potential for miniaturized photonics devices

Abstract

Bound states in the continuum (BICs) are an excellent platform enabling highly efficient light-matter interaction in applications for lasing, nonlinear generation, and sensing. However, the current focus in implementing BICs has primarily been on single sharp resonances, limiting the extent of electric field enhancement for multiple resonances. In this study, we conducted experimental demonstrations to showcase how metasurfaces can enable the control of symmetry-broken and Friedrich-Wintgen BICs by leveraging the asymmetry of split resonant rings. This approach allows for the existence of multiple free-control BIC resonances and tailored enhancement of controlling light-matter interactions. We have conducted further experiments to validate the effectiveness and performance of our approach for identification of the distinct fingerprint of {\alpha}-lactose with high sensitivity using only one single metasurface. These findings present a novel and efficient platform for the development of miniaturized and chip-scale photonics devices with intense light-matter interaction.