title: Quantum up-conversion of squeezed vacuum states from 1550 to 532 nm.
abstract: Squeezed vacuum states constitute a particularly useful resource in quantum information as well as in quantum metrology. The frequency conversion of these states is important to provide the bridge between different wavelengths within a sequence of downstream applications and also to provide a way for squeezed-state generation at so-far inaccessible wavelengths. Here we demonstrate the external quantum up-conversion of carrier-light-free squeezed vacuum states for the first time. Our result proves that nondegenerate sum-frequency generation preserves the coherences that are present between photon pairs and higher-order photon pairs of the squeezed input state.
authors.affiliation: Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut) and Institut für Gravitationsphysik der Leibniz Universität Hannover, Callinstraße 38, 30167 Hannover, Germany.
authors.forename: Christina E
authors.initials: CE
authors.lastname: Vollmer
authors.affiliation: Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut) and Institut für Gravitationsphysik der Leibniz Universität Hannover, Callinstraße 38, 30167 Hannover, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Baune
authors.affiliation: Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut) and Institut für Gravitationsphysik der Leibniz Universität Hannover, Callinstraße 38, 30167 Hannover, Germany.
authors.forename: Aiko
authors.initials: A
authors.lastname: Samblowski
authors.affiliation: Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut) and Institut für Gravitationsphysik der Leibniz Universität Hannover, Callinstraße 38, 30167 Hannover, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Eberle
authors.affiliation: Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut) and Institut für Gravitationsphysik der Leibniz Universität Hannover, Callinstraße 38, 30167 Hannover, Germany.
authors.forename: Vitus
authors.initials: V
authors.lastname: Händchen
authors.affiliation: Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic.
authors.forename: Jaromír
authors.initials: J
authors.lastname: Fiurášek
authors.affiliation: Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut) and Institut für Gravitationsphysik der Leibniz Universität Hannover, Callinstraße 38, 30167 Hannover, Germany.
authors.forename: Roman
authors.initials: R
authors.lastname: Schnabel