Correlated photon pairs generated from a warm atomic ensemble

TL;DR

This paper reports on the generation and characterization of correlated photon pairs from a warm rubidium vapor, highlighting how medium properties influence biphoton temporal correlations and potential for entanglement applications.

Contribution

It demonstrates the generation of correlated photon pairs in a hot atomic ensemble and explores how medium dispersive properties affect their temporal characteristics.

Findings

Short correlation times in optically thick samples due to off-resonant pair generation

Modification of linear response enables near-resonant photon pairs for entanglement

Photon pairs generated at 780 nm and 1367 nm with measurable cross-correlation functions

Abstract

We present measurements of the cross-correlation function of photon pairs at 780 nm and 1367 nm, generated in a hot rubidium vapor cell. The temporal character of the biphoton is determined by the dispersive properties of the medium where the pair generation takes place. We show that short correlation times occur for optically thick samples, which can be understood in terms of off-resonant pair generation. By modifying the linear response of the sample, we produce near-resonant photon pairs, which could in principle be used for entanglement distribution.