Photon scattering from strongly driven atomic ensembles

TL;DR

This paper analyzes the second-order correlation functions of light emitted from strongly driven atomic ensembles, revealing spectral peak separation, photon bunching, non-classical statistics, and ensemble disorder effects.

Contribution

It introduces a detailed analysis of spectral correlations and photon statistics in strongly driven atomic clouds, including violation of classical inequalities and comparison of disorder averaging methods.

Findings

Spectral peaks exhibit photon bunching and super/sub-Poissonian statistics.

Violation of Cauchy-Schwarz inequality for certain spectral bands.

Emitted light intensity scales with the square of atom number.

Abstract

The second order correlation function for light emitted from a strongly and near-resonantly driven dilute cloud of atoms is discussed. Because of the strong driving, the fluorescence spectrum separates into distinct peaks, for which the spectral properties can be defined individually. It is shown that the second-order correlations for various combinations of photons from different spectral lines exhibit bunching together with super- or sub-Poissonian photon statistics, tunable by the choice of the detector positions. Additionally, a Cauchy-Schwarz inequality is violated for photons emitted from particular spectral bands. The emitted light intensity is proportional to the square of the number of particles, and thus can potentially be intense. Three different averaging procedures to model ensemble disorder are compared.