Photonic Crystal Fiber Source of Quantum Correlated Photon Pairs in the 1550nm Telecom Band

A source of quantum correlated photon pairs in the 1550nm telecom band obtained by a pumping 11m photonic crystal fiber with 10ps pulse trains is experimentally demonstrated. We investigate how the birefringence of the fiber influences the purity of the photon pairs. We also present the frequency correlation of the signal and idler photon pairs. The experimental results are useful for developing a compact source of photon pairs well suited for quantum communication.