We characterize a source of photon pairs based on cascade decay in a cold ${}^{87}\mathrm{Rb}$ ensemble. This source is particularly suited to generate photons for interaction with ${}^{87}\mathrm{Rb}$ based atomic systems. We experimentally investigate the dependence of pair generation rate, single photon heralding efficiency, and bandwidth as a function of the number of atoms, detuning, and intensity of the pump beams. The observed power and detuning behaviors can be explained by the steady-state solution of an established three-level model of an atom. Measurements presented here provide a useful insight on the optimization of this kind of photon-pair source.

• Received 6 June 2018

DOI:https://doi.org/10.1103/PhysRevA.98.023835