Very high resolution velocimetry by recoil induced resonances

Stimulated Raman transitions between two motional states of a ground state atom can cause a controlled momentum exchange with the light field (the internal structure of the atom plays no role). Such stimulated Optical Compton Scattering (SOCS) has been used for velocimetry in a thermal atomic beam. This method of detection utilizes the recoil effect of an atom on absorption, or stimulated emission of a photon to probe the velocities of atoms directly. A presentation of the very high resolution of this method compared to ballistic methods in-spite of where the measurement is done, is given. The implementation of SOCS to measure Doppler and sub-Doppler cooling processes as well as changes in velocities is presented.