EVANESCENT LIGHT-WAVE ATOMIC FUNNEL - A TANDEM HOLLOW-FIBER, HOLLOW-BEAM APPROACH

We propose an atomic funnel consisting of a dark hollow, divergent las er beam and an evanescent light in a short micron-sized hollow optical fiber. The cold atoms extracted from a magneto-optical trap experienc e effective Sisyphus cooling in the dark hollow beam. We calculate the potential barriers for atomic guiding, in the evanescent Light and th e dark hollow beam, and analyze the atomic losses during the guiding a nd funneling process. Our results show that the equilibrium three-dime nsional root-mean-square momentum of about 4.5 (h) over bar k (tempera ture similar to 2.5 mu K) and the funneling efficiency of about 95% co uld be obtained. A low-velocity, intense coherent atomic beam can be g enerated in this funnel scheme and its potential applications in atom optics are briefly discussed.