Raman amplification with cold atoms in a hollow-core fiber

A fiber-confined atomic ensemble is a promising platform to explore non-classical light generation, such as heralded single photons, entangled photon-pairs, and multi-photon states. Additionally, this platform can also be used to study seeded nonlinear processes and their resulting emission. Here, we theoretically and experimentally study the Raman amplification of weak laser pulses and single-photon pulses produced by a quantum dot [1] propagating through an ensemble of cold caesium atoms confined inside a hollow-core fiber. A quantum optical description of spontaneous and stimulated Raman scattering helps us study propagation and photon statistics of the transmitted signal in both cases of weak coherent pulses and single-photons.

[1]: Maruf, R. A., Venuturumilli, S., Bharadwaj, D., Anderson, P., Qiu, J., Yuan, Y., Zeeshan, M., Semnani, B. Poole, P. J., Dalacu, D., et al., “Widely tunable solid-state source of single-photons matching an atomic transition,” arXiv preprint arXiv:2309.06734 (2023).