Generation of Narrow-Bandwidth Paired Photons: Use of a Single Driving Laser

Abstract

We describe a generator of narrow-band paired photons. A single retroreflected Ti:sapphire laser is used to cool, render transparent, and parametrically pump a cloud of ${}^{87}\mathrm{Rb}$ atoms. We attain a paired-photon generation rate into opposing fibers of $600\mathrm{\text{counts}}/\mathrm{s}$ with an intensity correlation function that has a width of 5 ns, and violates the Cauchy-Schwartz criteria by a factor of 2000.