The second is the SI time unit defined from the frequency of the transition radiation between two hyperfine levels of the fundamental state of the cesium 133 atom. The frequency of this radiation is in the microwave range (around 9 GHz). In recent years, however, several frequency references developed in national time metrology institutes have been providing radiation whose frequency is in the optical domain.
Objectives
Integrating optical clocks into the calculation of international time scales
Summary
Find here the detailled description of the project:
Publications and communications
MARGOLIS H.S., GODUN R.M., GILL P., JOHNSON L.A.M., SHEMAR S.L., WHIBBERLEY P.B., CALONICO D., LEVI F., LORINI L., PIZZOCARO M., DELVA P., BIZE S., ACHKAR J., DENKER H., TIMMEN L., VOIGT C., FALKE S., PIESTER D., LISDAT C., STERR U., VOGT S., WEYERS S., GERSL J., LINDVALL T. and MERIMAA M., “International timescales with optical clocks (ITOC)”, Proceedings of the 2013 Joint European Frequency and Time Forum and International Frequency Control Symposium, 2013, 908–911.
GERŠL J., DELVA P. and WOLF P., “Relativistic corrections for time and frequency transfer in optical fibres”, Metrologia, 52, 2015, 552–564.
ABGRALL M., CHUPIN B., DE SARLO L., GUÉNA J., LAURENT P., LE COQ Y., LE TARGAT R., LODEWYCK J., LOURS M., ROSENBUSCH P., ROVERA G. D. and BIZE S., “Atomic fountains and optical clocks at SYRTE: Status and perspectives”, Comptes Rendus de Physique, 16, 461–470, 2015.
DE SARLO L., FAVIER M., TYUMENEV R. and BIZE S., “A mercury optical lattice clock at LNE-SYRTE”, Journal of Physics: Conference Series, 723, 2016, 012017.
LISDAT C., GROSCHE G., QUINTIN N., SHI C., RAUPACH S.M.F., GREBING C., NICOLODI D., STEFANI F., AL-MASOUDI A., DÔRSCHER S., HÄFNER S., ROBYR J.-L., CHIODO N., BILICKI S., BOOKJANS E., KOCZWARA A., KOKE S., KUHL A., WIOTTA F., MEYNADIER F., CAMISARD E., ABGRALL M., LOURS M., LEGERO T., SCHNATZ H., STERR U., DENKER H., CHARDONNET C., LE COQ Y., SANTARELLI G., AMY-KLEIN A., LE TARGAT R., LODEWYCK J., LOPEZ O. and POTTIE P.-E., “A clock network for geodesy and fundamental science”, 2015, arXiv :1511.07735.
TYUMENEV R., FAVIER M., BILICKI S., BOOKJANS E., LE TARGAT R., LODEWYCK J., NICOLODI D., LE COQ Y., ABGRALL M., GUÉNA J., DE SARLO L. and BIZE S., “Comparing a mercury optical lattice clock with microwave and optical frequency standards”, 2016, arXiv : 1603.02026.
LODEWYCK J., BILICKI S., BOOKJANS E., ROBYR J.-L., SHI C., VALLET G., LE TARGAT R., NICOLODI D., LE COQ Y., GUÉNA J., ABGRALL M., ROSENBUSCH P. and BIZE S., “Optical to microwave clock frequency ratios with a nearly continuous strontium optical lattice clock”, 2016, arXiv : 1605.03878.
Partners
- NPL (UK),
- CMI (CZ),
- INRIM (IT),
- VTT (FI),
- PTB (DE),
- LUH (DE)