All-fiber photon-pair source for quantum communications.

In this letter, we present a source of quantum-correlated photon pairs based on parametric fluorescence in a fiber Sagnac loop. The photon pairs are generated in the 1550-nm fiber-optic communication band and detected with InGaAs-InP avalanche photodiodes operating in a gated Geiger mode. A generation rate > 103 pairs/s is observed, which is limited by the detection electronics at present. We also demonstrate the nonclassical nature of the photon correlations in the pairs. This source, given its spectral properties and robustness, is well suited for use in fiber-optic quantum communication and cryptography networks [ABSTRACT FROM PUBLISHER]