Quantum Interference Experiments with Frequency Entangled Photon Pairs at 1.5 ㎛ Telecommunication Band

Abstract

We performed experiments on Hong-Ou-Mandel type two-photon interference with frequency entangled photon pairs at 1.5 μm telecommunication band generated through femtosecond pulsed spontaneous parametric down-conversion. Two different angular frequencies   and   were selected using CWDM(coarse wavelength division multiplexing) filters at the output ports of the interferometer. The coincidence counting rates were measured with varying path-length difference between the two interferometer arms to observe the two-photon interference patterns of spatial beating. The obtained visibilities in the net coincidence were close to the theoretical limit of 100%.