Two-oscillator model of trapped-modes interaction in a nonlinear bilayer fish-scale metamaterial

TL;DR

This paper models the interaction of trapped modes in a nonlinear bilayer fish-scale metamaterial using a two-oscillator system, revealing unique spectral behaviors like bistability and multistability.

Contribution

It introduces a two-oscillator model to analyze nonlinear resonant interactions in a bilayer fish-scale metamaterial, highlighting the spectral line differences and nonlinear response features.

Findings

Identification of Lorentzian and Fano spectral lines in the system

Demonstration of bistability and multistability conditions

Observation of closed loops and overlapping in spectral lines

Abstract

We discuss the similarity between the nature of resonant oscillations in two nonlinear systems, namely, a chain of coupled Duffing oscillators and a bilayer fish-scale metamaterial. In such systems two different resonant states arise which differ in their spectral lines. The spectral line of the first resonant state has a Lorentzian form, while the second one has a Fano form. This difference leads to a specific nonlinear response of the systems which manifests itself in appearance of closed loops in spectral lines and bending and overlapping of resonant curves. Conditions of achieving bistability and multistability are found out.