Anderson localization in Bragg-guiding arrays with negative defects

TL;DR

This paper demonstrates that Anderson localization can occur in waveguide arrays with negative defects through Bragg reflection, with localization behavior influenced differently by diagonal and off-diagonal disorder.

Contribution

It reveals the possibility of Anderson localization in waveguide arrays with negative defects mediated by Bragg reflection, highlighting disorder effects on localization.

Findings

Localization occurs even with disorder affecting only defect waveguides.

Off-diagonal disorder increases localization degree monotonically.

Diagonal disorder can weaken localization under certain conditions.

Abstract

We show that Anderson localization is possible in waveguide arrays with periodically-spaced defect waveguides having lower refractive index. Such localization is mediated by Bragg reflection, and it takes place even if diagonal or off-diagonal disorder affects only defect waveguides. For off-diagonal disorder the localization degree of the intensity distributions monotonically grows with increasing disorder. In contrast, under appropriate conditions, increasing diagonal disorder may result in weaker localization.