On Stability of Flat Band Modes in a Rhombic Nonlinear Optical Waveguide Array

TL;DR

This paper investigates the stability of flat band modes in a nonlinear rhombic optical waveguide array, revealing that these modes are unstable below a certain power threshold and stable above it.

Contribution

It introduces an analysis of the stability conditions for flat band modes in a nonlinear waveguide array, highlighting the power threshold for stability.

Findings

Flat band modes are unstable below a specific power threshold.

Stability of flat band modes is achieved once the power exceeds this threshold.

The study provides insights into controlling waveguide mode stability in nonlinear optical systems.

Abstract

The quasi-one-dimensional rhombic array of the waveguides is considered. In the nonlinear case the system of equations describing coupled waves in the waveguides has the solutions that represent the superposition of the flat band modes. The property of stability of these solutions is considered. It was found that the flat band solution is unstable until the power threshold be attained.