Fundamental metrology with laser-cooled atoms and optical frequency combs
| Responsable du projet |
Pierre Thomann
Gianni Di Domenico |
| Collaborateur |
Stephane Schilt
Vladimir Dolgovskiy Lionel Tombez Alain Joyet |
| Résumé |
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. |
| Mots-clés |
laser cooling, frequency metrology, laser-atom, interactions, laser physics, tomic physics, laser cooling of atoms, optical frequeny combs, optical clocks, atomic clocks |
| Type de projet | Recherche fondamentale |
| Domaine de recherche | Autres secteurs de la physique |
| Source de financement | FNS - Encouragement de projets (Div. I-III) |
| Etat | Terminé |
| Début de projet | 1-4-2009 |
| Fin du projet | 31-3-2011 |
| Budget alloué | 428'283.00 |
| Autre information |
http://p3.snf.ch/projects-121987# |
| Contact | Pierre Thomann |