Microwave resonance on a laser-cooled cesium beam : prospects for a cesium frequency standard

Abstract The atomic clock transition ( F =3, M F =0↔F=4, M F =0) has been studied on a laser-cooled cesium atomic beam. Diode lasers have been used for laser cooling of the atoms, and for preparation and detection of the microwave transition. Both Rabi spectra and Ramsey fringes have been obtained. The observed lineshapes are characteristic of the narrow velocity distribution of the atoms. The residual width of the velocity distribution was estimated from the observation of Rabi oscillations. The high signal-to-noise ratio of the experimental spectra demonstrate the attractive possibilities opened by laser cooling in spectroscopy and frequency standard applications.