Narrowband photon pair source compatible with solid state quantum memories

Abstract

The generation of narrowband photon pairs compatible with solid state quantum memories is shown and analysed. This study is made in two different steps. In the beginning we implement a photon pair source with a periodically poled lithium niobate crystal in free space configuration. The photon pairs are characterized and their cross-correlation is measured. The source is also used as heralded single photon source, with the single photon character shown with a direct antibunching measurement. In a second step the crystal is embedded in a resonator to generate narrowband photons. Cavity enhancement is observed and the quantum behaviour of the photons is analysed. The final source is able to generate photon pairs with one photon at 606 nm while the other photon, at 1436 nm, will be used as herald. The biphoton bandwidth is <3 MHz making it compatible with a Pr3+:Y2SiO5 solid state quantum memory.