3D all optical local cooling in a bichromatic standing wave
Institut für Theoretische Physik, Universität Innsbruck,
Technikerstr. 25, 6020 Innsbruck, Austria
Revised: 5 November 1998
Published online: 15 April 1999
We theoretically investigate an all optical scheme for three-dimensional trapping and cooling of atoms in a single bichromatic standing wave with a Gaussian transverse intensity profile as, e.g. formed by two different longitudinal modes of a linear optical cavity. The atoms are cooled through an efficient Sisyphus mechanism and trapped at those anti-nodes (maxima) of the stronger field where the second weaker field has a node. This generates a large effective atom-field coupling as it is desired in nonlinear optical experiments with clouds of atoms. The scheme effects high local densities modulated at the beat frequency of the two involved modes. In the appropriate parameter regime the results from a three-dimensional semi-classical approach are confirmed by a 1D full QMCWF-simulation. Extending our model to a more realistic case, we include loss channels out of the system and repumping. Furthermore, we generalise our approach to Λ-type level schemes, which exhibit promising optical nonlinearities. Trapping and cooling of such atoms is predicted to be compatible with maintaining high cooperativities needed for large nonlinear effects.
PACS: 32.80.Pj – Optical cooling of atoms; trapping / 42.50.Vk – Mechanical effects of light on atoms, molecules, electrons, and ions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999