[en] We report the first observation of coherent backscattering of light from a sample of laser-cooled atoms. Rubidium 85 atoms are captured from a room-temperature vapor in a magneto-optical trap, and illuminated with a laser probe. The angular intensity distribution of the backscattered light is recorded on a cooled CCD detector. We observe a small enhancement factor in all polarization channels, including the 'helicity preserving' channel where the enhancement is only 1.08. This surprising observation is attributed to the existence of contrast reduction processes involving the atom's internal structure. (authors)
Source
Kaiser, R. (Universite de Nice Sophia Antipolis, Institut Non-Lineaire de Nice, INLN, 06 - Valbonne (France)); Westbrook, C. (Institut d'Optique, Centre Scientifique d'Orsay, 91 (France)); David, F. (Ecole de Physique des Houches, 38 - Grenoble (France); CEA Saclay, SPht, 91 - Gif sur Yvette (France)); 714 p; ISBN 2-86883-499-X; 
; 2001; p. 699-714; Conference on coherent atomic matter waves; Les Houches (France); 27 Jul - 27 Aug 1999; 14 refs.
; 2001; p. 699-714; Conference on coherent atomic matter waves; Les Houches (France); 27 Jul - 27 Aug 1999; 14 refs.
[en] We study light coherent transport in the weak localization regime using magneto-optically cooled strontium atoms. The coherent backscattering cone is measured in the four polarization channels using light resonant with a Jg=0→Je=1 transition of the strontium atom. We find an enhancement factor close to 2 in the helicity preserving channel, in agreement with theoretical predictions. This observation confirms the effect of internal structure as the key mechanism for the contrast reduction observed with a rubidium cold cloud [G. Labeyrie et al., Phys. Rev. Lett. 83, 5266 (1999)]. Experimental results are in good agreement with Monte Carlo simulations taking into account geometry effects
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