Dissipative defect modes in periodic structures

TL;DR

This paper demonstrates the existence of stable dissipative defect modes in nonlinear periodic optical lattices with gain and loss, revealing how their shapes depend on the propagation constant within the spectral gap.

Contribution

It introduces the concept of dissipative defect modes supported by nonlinear lattices with localized gain and strong two-photon absorption, expanding understanding of stable localized states in such media.

Findings

Stable one-hump and two-hump dissipative defect modes identified.

Mode shapes depend on the propagation constant within the spectral gap.

Gain-loss balance determines the existence and properties of the modes.

Abstract

We show that periodic optical lattices imprinted in cubic nonlinear media with strong two-photon absorption and localized linear gain landscapes support stable dissipative defect modes in both focusing and defocusing media. Their shapes and transverse extent are determined by the propagation constant that belongs to a gap of the lattice spectrum which, in turn, is determined by the relation between gain and losses. One-hump and two-hump dissipative defect modes are obtained.