Measurement of the hydrogen 1S- 2S transition frequency by phase coherent comparison with a microwave cesium fountain clock

M Niering; R Holzwarth; J Reichert; P Pokasov; T Udem; M Weitz; TW Hansch; P Lemonde; G Santarelli; M Abgrall; P Laurent; C Salomon; A Clairon

doi:10.1103/PhysRevLett.84.5496

Measurement of the hydrogen 1S- 2S transition frequency by phase coherent comparison with a microwave cesium fountain clock

Phys Rev Lett. 2000 Jun 12;84(24):5496-9. doi: 10.1103/PhysRevLett.84.5496.

Authors

M Niering¹, R Holzwarth, J Reichert, P Pokasov, T Udem, M Weitz, TW Hansch, P Lemonde, G Santarelli, M Abgrall, P Laurent, C Salomon, A Clairon

Affiliation

¹ Max-Planck-Institut fur Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.

PMID: 10990978
DOI: 10.1103/PhysRevLett.84.5496

Abstract

We report on an absolute frequency measurement of the hydrogen 1S-2S two-photon transition in a cold atomic beam with an accuracy of 1.8 parts in 10(14). Our experimental result of 2 466 061 413 187 103(46) Hz has been obtained by phase coherent comparison of the hydrogen transition frequency with an atomic cesium fountain clock. Both frequencies are linked with a comb of laser frequencies emitted by a mode locked laser.