Transverse localization of light and its dependence on the phase-front curvature of the input beam in a disordered optical waveguide lattice

TL;DR

This study explores how the phase-front curvature of an input light beam affects its transverse localization in a disordered optical waveguide lattice, showing that curvature can degrade localization quality and influence propagation modes.

Contribution

It demonstrates through numerical analysis that phase-front curvature significantly impacts light localization in disordered waveguides, a factor not thoroughly examined before.

Findings

Plane phase-front beams localize more effectively.

Curved phase-front beams exhibit faster transition to localized states.

Phase-front curvature degrades localization quality.

Abstract

We investigate the influence of the phase-front curvature of an input light beam on the transverse localization of light by choosing an evanescently coupled disordered one-dimensional semi-infinite waveguide lattice as an example. Our numerical study reveals that a finite phase front curvature of the input beam indeed plays an important role and it could degrade the quality of light localization in a disordered dielectric structure. More specifically, a faster transition from ballistic mode of beam propagation due to diffraction to a characteristic localized state is observed in case of a continuous wave (CW) beam, whose phase-front is plane as compared to one having a curved phase front.