A clock transition for a future optical frequency standard with trapped atoms

I. Courtillot (1) , A. Quessada (1) , R. P. Kovacich (1) , A. Brusch (1) , D. Kolker (1) , J-J. Zondy (1) , G. D. Rovera (1) , P. Lemonde (1)

1 SYRTE - Systèmes de Référence Temps Espace

We report the first direct excitation of the strongly forbidden 5s2 1S0-5s5p 3P0 transition in 87Sr. Its frequency is 429 228 004 235 (20) kHz. A resonant laser creates a small leak in a magneto-optical trap (MOT): atoms build up to the metastable 3P0 state and escape the trapping process, leading to a detectable decrease in the MOT fluorescence. This line has a natural width of 10^{-3} Hz and can be used for a new generation of optical frequency standards using atoms trapped in a light shift free dipole trap.

Domaines: Physique Atomique [physics.atom-ph]

I. Courtillot, A. Quessada, R. P. Kovacich, A. Brusch, D. Kolker, et al.. A clock transition for a future optical frequency standard with trapped atoms. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2003, 68, pp.030501(R). ⟨10.1103/PhysRevA.68.030501⟩. ⟨hal-00016399⟩