The output of a mode-locked femtosecond laser is used for precision single-photon spectroscopy of ^133 Cs in an atomic beam. By changing the laser's repetition rate, the cesium D1(6s ²S_1/2 --> 6p ²P_1/2) and D2(6s ²S_1/2 --> 6p ²P_3/2) transitions are detected and the optical frequencies are measured with accuracy similar to that obtained with a cw laser. Control of the femtosecond laser repetition rate by use of the atomic fluorescence is also implemented, thus realizing a simple cesium optical clock.
© 2005 Optical Society of America
(300.6320) Spectroscopy : Spectroscopy, high-resolution
V. Gerginov, C. E. Tanner, S. A. Diddams, A. Bartels, and L. Hollberg, "High-resolution spectroscopy with a femtosecond laser frequency comb," Opt. Lett. 30, 1734-1736 (2005)