# Resonant transport and near-field effects in photonic glasses

## TL;DR

This paper develops a model using an effective refractive index to accurately predict light transport properties in dense photonic glasses, capturing resonant scattering and near-field effects, validated by simulations and experiments.

## Contribution

It introduces a parameter-free model based on the energy-density coherent potential approximation to describe light transport in dense photonic glasses.

## Key findings

- Model accurately predicts transport mean free path.
- Resonant scattering and near-field effects are captured.
- Good agreement with experiments and simulations.

## Abstract

A fundamental quantity in multiple scattering is the transport mean free path the inverse of which describes the scattering strength of a sample. In this paper, we emphasize the importance of an appropriate description of the effective refractive index $n_{\mathrm{eff}}$ in multiple light scattering to accurately describe the light transport in dense photonic glasses. Using $n_{\mathrm{eff}}$ as calculated by the energy-density coherent potential approximation we are able to predict the transport mean free path of monodisperse photonic glasses. This model without any fit parameter is in qualitative agreement with numerical simulations and in fair quantitative agreement with spectrally resolved coherent backscattering measurements on new specially synthesized polystyrene photonic glasses. These materials exhibit resonant light scattering perturbed by strong near-field coupling, all captured within the model. Our model might be used to maximize the scattering strength of high index photonic glasses, which are a key in the search for Anderson localization of light in three dimensions.