Cold trapped atoms detected with evanescent waves
Van der Waals–Zeeman Institute, University of Amsterdam,
Valckenierstraat 65, 1018 XE Amsterdam, The Netherlands
Corresponding author: a firstname.lastname@example.org
Published online: 8 October 2002
We demonstrate the in situ detection of cold 87Rb 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 atoms at a density 100 times higher than the falling atoms.
PACS: 32.80.Pj – Optical cooling of atoms; trapping / 42.25.Bs – Wave propagation, transmission and absorption
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002