Institut des Sciences Moléculaires d'Orsay



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Accueil > Séminaires > Année 2023 > Séminaire d’An Tran (28 nov)

Séminaire d’An Tran (28 nov)

Time and Frequency Department, National Physical Laboratory, United Kingdom

par Martrenchard-Barra Séverine - 11 novembre (modifié le 18 novembre)

Demonstration of time scales steered by NPL and OP’s optical atomic clocks

In this talk, we first introduce the research activities within the Optical Frequency Metrology group at the National Physical Laboratory (NPL), including the development and operation of state-of-the-art optical atomic clocks ; optical frequency comparison and dissemination techniques ; and trace gas detection. We then present the application of optical atomic clocks at NPL and the Observatoire de Paris (OP) to generate real-time optically steered timescales. Via optical frequency combs, two optical time scales UTCx(NPL) and UTCx(OP) were realized at the same time by calibrating the frequency of hydrogen masers against the local optical atomic clocks at NPL and OP. The performance of these experimental timescales has been analyzed via local comparisons against the traditional UTC(k) (steered by Cs fountain microwave clocks) and via remote comparisons using satellite techniques to link the two UTCx(k). To our knowledge, this is the first-ever comparison of two independent “optical time scale” prototypes, and the results demonstrate the capacity of optical atomic clocks to produce highly stable and accurate timescales, towards a redefinition of the SI second.

NPL : A. Tran, J. Tunesi, A. O. Parsons, A. Tofful, B. I. Robertson, M. Y. H. Johnson, C-H. Feng, M. Schioppo, E. A. Curtis, I. R. Hill, R. M. Godun, H. S. Margolis
OP : M. Abgrall, B. Chupin, P. Uhrich, L. Lorini, R. Le Targat, B. Pointard, J. Lodewyck