title: One- and two-photon quantum interferences in parametric four-wave mixing.
abstract: We report the observation of the interferometric response in parametric four-wave mixing in rubidium atoms excited by a pair of ultrashort pulses. For pulses with orthogonal polarizations and in the presence of the two-photon transition 5S-5D reveals a one-photon quantum interference, in contrast to the optical interference observed when the pulses have parallel polarization. For opposite circular polarizations no interference is observed in the fluorescence of the two-photon transition, in contrast to the one- and two-photon interferences exhibited in the nonlinear process.
authors.affiliation: Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil.
authors.forename: J
authors.initials: J
authors.lastname: Ferraz
authors.forename: L H
authors.initials: LH
authors.lastname: Acioli
authors.forename: S S
authors.initials: SS
authors.lastname: Vianna