La mesure du temps aujourd'hui

Emeric de Clercq (1, 2, 3) , Thomas Zanon-Willette (4) , Ouali Acef (1, 2, 3)

1 SYRTE - Systèmes de Référence Temps Espace
2 Métrologie des fréquences optiques
3 Références micro-ondes et échelles de temps
4 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique

This is a short review of the state of the art of the measurement of time in the metrology laboratories. After a brief recall of the successive definitions of the second, now defined on an atomic transition of the caesium atom, we present today atomic clocks: the Cs beam clock, still the workhorse of time metrology, and the Cs fountain clock based on cold atoms, which revolutionized the field. A promising new generation based on higher frequency transitions is coming, the optical clocks, the strontium clock is given as an example. Afterwards a few methods of clock comparison and clock signal dissemination are addressed.

Domaines: Astrophysique [astro-ph]

Emeric de Clercq, Thomas Zanon-Willette, Ouali Acef. La mesure du temps aujourd'hui. La Revue de l'électricité et de l'électronique, 2016, 1, pp.96. ⟨hal-03691970⟩