title: Generalized quantum interference of correlated photon pairs.
abstract: Superposition and indistinguishablility between probability amplitudes have played an essential role in observing quantum interference effects of correlated photons. The Hong-Ou-Mandel interference and interferences of the path-entangled photon number state are of special interest in the field of quantum information technologies. However, a fully generalized two-photon quantum interferometric scheme accounting for the Hong-Ou-Mandel scheme and path-entangled photon number states has not yet been proposed. Here we report the experimental demonstrations of the generalized two-photon interferometry with both the interferometric properties of the Hong-Ou-Mandel effect and the fully unfolded version of the path-entangled photon number state using photon-pair sources, which are independently generated by spontaneous parametric down-conversion. Our experimental scheme explains two-photon interference fringes revealing single- and two-photon coherence properties in a single interferometer setup. Using the proposed interferometric measurement, it is possible to directly estimate the joint spectral intensity of a photon pair source.
authors.affiliation: Department of Physics, Pusan National University Geumjeong-Gu, Busan 609-735, Korea.
authors.forename: Heonoh
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Physics, Pusan National University Geumjeong-Gu, Busan 609-735, Korea.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Physics, Pusan National University Geumjeong-Gu, Busan 609-735, Korea.
authors.forename: Han Seb
authors.initials: HS
authors.lastname: Moon