Ultra-bright omni-directional collective emission of correlated photon pairs from atomic vapors

TL;DR

This paper demonstrates a method using atomic vapors to generate ultra-bright, omni-directional correlated photon pairs with high efficiency and low background noise, leveraging multi-photon pumping and quantum coherence effects.

Contribution

It introduces a novel multi-photon pumping scheme in atomic vapors that achieves ultra-bright, omni-directional photon pair emission with suppressed background scattering and atomic heating.

Findings

Photon pairs emitted at rates of ~10^12 per second.

Emission occurs in the full 4π solid angle.

The system can produce narrow bandwidth photon pairs with lower rates.

Abstract

Spontaneous four-wave mixing can generate highly correlated photon pairs from atomic vapors. We show that multi-photon pumping of dipole-forbidden transitions in a recoil-free geometry can result in ultra-bright pair-emission in the full 4\pi solid angle, while strongly suppresses background Rayleigh scattering and associated atomic heating, Such a system can produce photon pairs at rates of ~ 10 ^12 per second, given only moderate optical depths of 10 ~ 100, or alternatively, the system can generate paired photons with sub-natural bandwidths at lower production rates. We derive a rate-equation based theory of the collective atomic population and coherence dynamics, and present numerical simulations for a toy model, as well as realistic model systems based on 133 Cs and 171 Yb level structures. Lastly, we demonstrate that dark-state adiabatic following (EIT) and/or timescale hierarchy protects the paired photons from reabsorption as they propagate through an optically thick sample.