Title :
Two-photon Ramsey fringes at 30 THz referenced to an H maser/Cs fountain via an optical-frequency comb at the 1-Hz level
Author :
Shelkovnikov, Alexander ; Grain, Christophe ; Butcher, Robert James ; Amy-Klein, Anne ; Goncharov, Andréi ; Chardonnet, Christian
Author_Institution :
Lab. de Phys. des Lasers, Univ. Paris, Villetaneuse, France
Abstract :
Aspects of two-photon Ramsey fringes in SF6 at 30 THz obtained with a 1-m separation between the two absorption zones are presented. The experiment is referenced to a primary standard, the Hydrogen maser/Cs fountain located at BNM-SYRTE, via a femtosecond laser frequency comb generator. This results in a stability below 1 Hz for 1000 s of averaging, and absolute frequency measurements to ±2 Hz which corresponds to 6×10-14 in relative frequency. Resolution of the hyperfine structure now approaches 10 Hz, while the fringe period of 200 Hz provides a frequency discriminator 100 times narrower than any other currently in use in the spectral region.
Keywords :
caesium; frequency standards; hydrogen; hyperfine structure; laser frequency stability; masers; sulphur compounds; two-photon processes; -2 to 2 Hz; 1 m; 1000 s; 200 Hz; 30 THz; Cs; H; H maser/Cs fountain; SF6; femtosecond laser frequency comb generator; frequency discriminator; frequency stability; hyperfine structure resolution; optical frequency comb; optical frequency standard; two-photon Ramsey fringes; Absorption; Frequency; Hydrogen; Laboratories; Laser theory; Masers; Optical saturation; Synthesizers; Ultrafast electronics; Ultrafast optics; $hbox SF_6$; Carbon dioxide lasers; frequency stability; optical-frequency standard;
Journal_Title :
Quantum Electronics, IEEE Journal of
DOI :
10.1109/JQE.2004.831621
