title: Polarization squeezing with cold atoms.
abstract: We study the interaction of a nearly resonant linearly polarized laser beam with a cloud of cold cesium atoms in a high finesse optical cavity. We show theoretically and experimentally that the cross-Kerr effect due to the saturation of the optical transition produces quadrature squeezing on both the mean field and the orthogonally polarized vacuum mode. An interpretation of this vacuum squeezing as polarization squeezing is given and a method for measuring quantum Stokes parameters for weak beams via a local oscillator is developed.
authors.affiliation: Laboratoire Kastler Brossel, Université Pierre et Marie Curie, Ecole Normale Supérieure et CNRS, Case 74, 4 place Jussieu, 75252 Paris Cedex 05, France.
authors.forename: V
authors.initials: V
authors.lastname: Josse
authors.forename: A
authors.initials: A
authors.lastname: Dantan
authors.forename: L
authors.initials: L
authors.lastname: Vernac
authors.forename: A
authors.initials: A
authors.lastname: Bramati
authors.forename: M
authors.initials: M
authors.lastname: Pinard
authors.forename: E
authors.initials: E
authors.lastname: Giacobino