Slow diffusion of light in a cold atomic cloud.
We study the diffusive propagation of multiply scattered light in an optically thick cloud of cold rubidium atoms illuminated by a quasiresonant laser beam. In the vicinity of a sharp atomic resonance, the energy transport velocity of the scattered light is almost 5 orders of magnitude smaller than the vacuum speed of light, reducing strongly the diffusion constant. We verify the theoretical prediction of a frequency-independent transport time around the resonance. We also observe the effect of the residual velocity of the atoms at long times.
Labeyrie
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Laboratoire Ondes et Désordre, FRE 2302 CNRS, 1361 route des Lucioles, F-06560 Valbonne, France. Guillaume.Labeyrie@inln.cnrs.fr
Vaujour
E
E
Müller
C A
CA
Delande
D
D
Miniatura
C
C
Wilkowski
D
D
Kaiser
R
R