title: Absolute frequency measurement of a SF6 two-photon line by use of a femtosecond optical comb and sum-frequency generation.
abstract: We demonstrate a new, simple technique for measuring IR frequencies near 30 THz by using a femtosecond (fs) laser optical comb and sum-frequency generation. The optical frequency is directly compared with the distance between two modes of the fs laser, and the resultant beat note is used to control this distance, which depends only on the repetition rate of the fs laser. The absolute frequency of a CO2 laser stabilized onto a SF6 two-photon line has been measured for the first time to the authors' knowledge. This line is an attractive alternative to the usual saturated absorption OsO4 resonances used for the stabilization of CO2 lasers. First results demonstrate a fractional Allan deviation of 3 x 10(-14) at 1 s.
authors.affiliation: Laboratoire de Physique des Lasers, Unité Mixte de Recherche 7538, Centre National de la Recherche Scientifique, Université Paris 13, 99 Avenue J.-B. Clément, 93430 Villetaneuse, France. amy@galilee.univ-paris13.fr
authors.forename: Anne
authors.initials: A
authors.lastname: Amy-Klein
authors.forename: Andrei
authors.initials: A
authors.lastname: Goncharov
authors.forename: Mickaël
authors.initials: M
authors.lastname: Guinet
authors.forename: Christophe
authors.initials: C
authors.lastname: Daussy
authors.forename: Olivier
authors.initials: O
authors.lastname: Lopez
authors.forename: Alexander
authors.initials: A
authors.lastname: Shelkovnikov
authors.forename: Christian
authors.initials: C
authors.lastname: Chardonnet