The independent scattering approximation in the saturated regime

TL;DR

This paper compares the independent scattering approximation with a master equation approach for light scattering by atoms, highlighting their agreement in certain regimes and differences in others, especially under high saturation and near-field conditions.

Contribution

It demonstrates the conditions under which the independent scattering approximation aligns with the master equation approach and identifies regimes where they diverge.

Findings

Agreement between methods in unsaturated or widely separated atoms

Differences arise in near-field and highly saturated regimes

The approaches diverge significantly under high saturation and close proximity

Abstract

We show that a saturable single-frequency elastic T-matrix approach to scattering of light by atoms agrees remarkably well with a master equation description in the regime of unsaturated atoms, or for large separation between the atoms. If the atoms are in each other's near-field and the saturation of the atoms is high enough, the two approaches yield different results.