Pump-probe spectroscopy and velocimetry of cold atoms in a slow beam - art. no. 043408

In this paper we report on the first purely "pump-probe" nonlinear laser sp ectroscopy results in a slow atomic beam. We have observed Raman, Rayleigh, and recoil-induced resonances (RIR) in a continuous beam of slow and cold cesium atoms extracted from a two-dimensional (2D) magneto-optical-trap (MO T) with the moving molasses technique. The RIR enabled us to measure the ve locity distribution. therefore the average speed (0.6-4 m/s) and temperatur e (50-500 muK) of the atomic beam. Compared to time of flight, this techniq ue has the advantage of being local, more sensitive in the low-velocity reg ime (v<1 m/s), and it gives access to transverse velocities and temperature s. Moreover. it may be extended to measure atomic velocities in the 2D MOT source of the atomic beam.