Generation of ideal thermal light in warm atomic vapor

TL;DR

This paper reports the experimental creation of near-ideal thermal light using warm atomic vapor, with controllable spectral bandwidth, suitable for various quantum and classical optical applications.

Contribution

It demonstrates a novel method to generate high-quality thermal light with adjustable bandwidth via spontaneous Raman emission in warm atomic vapor.

Findings

Photon statistics match Bose-Einstein distribution

Spectral bandwidth extended to hundreds of MHz

Thermal properties verified through correlation measurements

Abstract

We present the experimental generation of light with directly observable close-to ideal thermal statistical properties. The thermal light state is prepared using a spontaneous Raman emission in a warm atomic vapor. The photon number statistics is evaluated by both the measurement of second-order correlation function and by the detailed analysis of the corresponding photon number distribution, which certifies the quality of the Bose-Einstein statistics generated by natural physical mechanism. We further demonstrate the extension of the spectral bandwidth of the generated light to hundreds of MHz domain while keeping the ideal thermal statistics, which suggests a direct applicability of the presented source in a broad range of applications including optical metrology, tests of robustness of quantum communication protocols, or quantum thermodynamics.