2002/05/31 by R. A. Cornelussen, A. H. van Amerongen, B. T. Wolschrijn +2
Physics and Astronomy · #physics.atom-ph
paper · pdf · doi:10.1140/epjd/e2002-00205-1
published as Eur. Phys. J. D 21, 347-351 (2002) · 5 pages, 3 figures
arxiv created 2002/10/09 · arxiv updated 2009/12/01
We demonstrate the in situ detection of cold 87 Rb atoms near a dielectric surface using the absorption of a weak, resonant evanescent wave. We have used this technique in time of flight experiments determining the density of atoms falling on the surface. A quantitative understanding of the measured curve was obtained using a detailed calculation of the evanescent intensity distribution. We have also used it to detect atoms trapped near the surface in a standing-wave optical dipole potential. This trap was loaded by inelastic bouncing on a strong, repulsive evanescent potential. We estimate that we trap 1.5 x 10 4 atoms at a density 100 times higher than the falling atoms.