Abstract

In this paper we present the results of an investigation into the dynamics of interactions between ultra cooled atomic beams and optical standing fields. Recent advances in experimental techniques for the cooling and trapping of atoms have realised a number of new phenomena in atom optics.^[1,2,3] For example, atoms with extremely narrow momentum spread can be selected by the atom-photon interaction.^[4] The principle is that for the long interaction times now possible, the non-dissipative resonant momentum transfer between the atoms and photons at large detuning does not heat or cool the atomic beam. Since each photon emission and absorption cycle shifts the atomic momentum by twice the photon momentum 2ħk, coupling only occurs between the +ħk and −ħk momentum components of the atomic beam parallel to the field. This is the only momentum shift which satisfies energy conservation. We investigate the limiting resolution of the selected atomic velocity due to the finite interaction time, finite field strength, and also due to the spatial extent of the beam waist.

© 1992 IQEC