Generation of pulsed-correlated photon pairs in the 1550nm band using a PPLN waveguide

We report a generation of pulsed correlated photon pairs in the 1550 nm band which is essential to long-distance fiber-optic quantum information and communication. We performed two-photon interference experiments using a Mach-Zehnder interferometer to demonstrate the quantum correlation of photon pairs. The two-photon interference was observed with a visibility of 84% when the two arm lengths were balanced.