Scaling analysis of transverse Anderson localization in a disordered optical waveguide

TL;DR

This paper introduces a statistical tool called mode-width PDF to analyze transverse Anderson localization in disordered optical waveguides, demonstrating that smaller structures can reliably predict localization properties, thus reducing computational effort.

Contribution

The paper presents the mode-width PDF as a new method for studying Anderson localization and shows its scaling behavior, enabling analysis with smaller structures.

Findings

Mode-width PDF effectively characterizes localization properties.

Scaling analysis shows convergence to a terminal configuration.

Cladding refractive index influences mode extension and image transport.

Abstract

The intention of this manuscript is twofold. First, the mode-width probability density function (PDF) is introduced as a powerful statistical tool to study and compare the transverse Anderson localization properties of a disordered one dimensional optical waveguide. Second, by analyzing the scaling properties of the mode-width PDF with the transverse size of the waveguide, it is shown that the mode-width PDF gradually converges to a terminal configuration. Therefore, it may not be necessary to study a real-sized disordered structure in order to obtain its statistical localization properties and the same PDF can be obtained for a substantially smaller structure. This observation is important because it can reduce the often demanding computational effort that is required to study the statistical properties of Anderson localization in disordered waveguides. Using the mode-width PDF, substantial information about the impact of the waveguide parameters on its localization properties is extracted. This information is generally obscured when disordered waveguides are analyzed using other techniques such as the beam propagation method. As an example of the utility of the mode-width PDF, it is shown that the cladding refractive index can be used to quench the number of extended modes, hence improving the contrast in image transport properties of disordered waveguides.