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Cold trapped atoms detected with evanescent waves

R. A. Cornelussen·A. H. van Amerongen·B. T. Wolschrijn·R. J. C. Spreeuw·H. B. van Linden van den Heuvell
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Abstract

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.

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R. A. Cornelussen, A. H. van Amerongen, B. T. Wolschrijn, R. J. C. Spreeuw, H. B. van Linden van den Heuvell. 2002-10-09. Cold trapped atoms detected with evanescent waves. https://doi.org/10.1140/epjd%2Fe2002-00205-1

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