Fundamental metrology with laser-cooled atoms and optical frequency combs
Project responsable Pierre Thomann
Gianni Di Domenico
Team member Stephane Schilt
Vladimir Dolgovskiy

Lionel Tombez

Alain Joyet
Abstract Fundamental metrology with laser-cooled atoms and optical frequency combs Principal investigator: Prof. Pierre Thomann, LTF laboratoire Temps-Fréquence - Université de Neuchâtel Lead : Time is the physical quantity which can be measured with the highest precision, using atomic clocks as measuring sticks. Further improvements are however required in many applications, such as telecommunications and satellite navigation systems, where the performance of yesterday's best clocks is now used on a routine basis. This research focuses on improving the accuracy of existing reference clocks and on new types of atomic clocks. Summary: The precise measurement of time relies on atomic clocks, i.e. clocks whose pendulum is made of atoms oscillating at frequencies ranging from 1010 to 1015 Hz. This research focuses on: 1) improving the stability and the accuracy of an existing reference atomic clock based on an original principle - a continuous fountain of laser-cooled cesium atoms - , and 2) the realization of an ultrastable microwave oscillator based on a laser, stabilized on an optical cavity, and an optical frequency comb. The short-term stability of such an all-optical microwave oscillator is expected to surpass that of active hydrogen masers. Goal: 1) Reference atomic clocks (primary frequency standards) are used in basic metrology, to generate the international atomic time scale (UTC). The laser-cooled fountain clock FOCS-2 is developed in collaboration with - and with the support of - METAS, the Swiss institute of metrology. Its original design is meant to give new insights in the fundamental limits of cold-atom clocks. Other applications of primary clocks are in testing fundamental physical theories. 2) Ultrastable all-optical microwave generators are only beginning to be used in the most critical applications in metrology laboratories. However, their use will soon spread to all present applications of hydrogen masers, e.g. radio-astronomy, geophysics, and space research. Signification: Although time measurements are by far the most precise of all physical measurements, progress in this field is entirely driven by applications: atomic clocks are at the heart of large-scale technological developments such as global, high capacity telecommunication networks and satellite-based navigation and positioning systems (e.g. GPS, Galileo). Thanks to a consistent effort in basic research, applied research and industrial transfer, Swiss industry and academia now make a substantial contribution to the fabrication and use of state-of-the art atomic clocks in such large-scale systems, both in ground and in space applications.
Keywords laser cooling, frequency metrology, laser-atom, interactions, laser physics, tomic physics, laser cooling of atoms, optical frequeny combs, optical clocks, atomic clocks
Type of project Fundamental research project
Research area Autres secteurs de la physique
Method of financing FNS - Encouragement de projets (Div. I-III)
Status Completed
Start of project 1-4-2009
End of project 31-3-2011
Overall budget 428'283.00
Additional info http://p3.snf.ch/projects-121987#
Contact Pierre Thomann