Multiplexing-oriented plasmon-MoS2 hybrid metasurfaces driven by nonlinear quasi bound states in the continuum

TL;DR

This paper introduces a wavelength-multiplexed nonlinear plasmon-MoS2 hybrid metasurface leveraging bound states in the continuum, enabling simultaneous processing and tuning of multiple nonlinear optical signals with enhanced susceptibility.

Contribution

It presents a novel quantum oscillator-based method to suppress and enhance nonlinear quasi BICs, improving control over nonlinear responses in plasmonic metasurfaces.

Findings

Demonstrated giant second-order nonlinear susceptibility of MoS2 in the infrared.

Proposed a physical model for nonlinear plasmonic BICs from classical and quantum perspectives.

Achieved narrower linewidths and smaller quantum decay rates for improved optical control.

Abstract

Rapid progress in nonlinear plasmonic metasurfaces enabled many novel optical characteristics for metasurfaces, with potential applications in frequency metrology, timing characterization and quantum information. However, the spectrum of nonlinear optical response was typically based upon the linear optical resonance. In this work, a wavelength-multiplexed nonlinear plasmon-MoS2 hybrid metasurface with suppression phenomenon was proposed, where multiple nonlinear signals could to be simultaneously processed and optionally tuned. A clear physical picture to depict the nonlinear plasmonic bound states in the continuum (BICs) was presented, from the perspective of both classical and quantum approaches. Particularly, beyond the ordinary plasmon-polariton effect, we numerically demonstrated a giant BIC-inspired second-order nonlinear susceptibility $10^{-5}$~$m/V$ of MoS2 in the infrared band. The novelty in our study lies in the presence of a quantum oscillator that can be adopted to both suppress and enhance the nonlinear quasi BICs. This selectable nonlinear BIC-based suppression and enhancement effect can optionally block undesired modes, resulting in narrower linewidth as well as smaller quantum decay rates, which is also promising in slow-light-associated technologies.