Fano resonances in saturable waveguide arrays

TL;DR

This paper investigates Fano resonances in a waveguide array with a nonlinear saturable impurity, revealing how light transmission can be controlled via nonlinear localized modes and scattering phenomena.

Contribution

It provides a closed-form solution for impurity modes and links Fano resonances to nonlinear waveguide scattering, offering a new method to control light transport.

Findings

Regions of complete transmission suppression identified

Nonlinear localized modes characterized

Fano resonances linked to scattering behavior

Abstract

We study a waveguide array with an embedded nonlinear saturable impurity. We solve the impurity problem in closed form and find the nonlinear localized modes. Next, we consider the scattering of a small-amplitude plane wave by a nonlinear impurity mode, and discover regions in parameter space where transmission is fully suppressed. We relate these findings with Fano resonances and propose this setup as a mean to control the transport of light across the array.