title: Experimental demonstration of a pure third-order optical parametric downconversion process.
abstract: We report what is, to the best of our knowledge, the first experiment on third-order optical difference frequency generation. The nonlinear medium is a phase-matched KTiOPO4 crystal pumped at 532 and 1665 nm in the picosecond regime. The proposed experimental configuration leads to an efficient and pure cubic process, with generation of 4.5 microJ/pulse at 1474 nm. This result opens the way to new quantum experiments on three-photon Greenberger-Horne-Zeilinger entanglement.
authors.affiliation: Laboratoire de Spectrométrie Physique, Unité Mixte de Recherche 5588, Université Joseph Fourier & Centre National de la Recherche Scientifique, 140 Avenue de la Physique, BP 87, F-38402 Saint Martin d'Heres Cedex, France.
authors.forename: J
authors.initials: J
authors.lastname: Douady
authors.forename: B
authors.initials: B
authors.lastname: Boulanger