Frankfurt 2006 – scientific programme

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SYRT: Radiation transport in random media

SYRT 1: Radiation transport in random media I

SYRT 1.2: Invited Talk

Friday, March 17, 2006, 11:30–12:00, HVI

Coherent backscattering of light in nonlinear media — •Thomas Wellens — Laboratoire Kastler Brossel, Université Pierre et Marie Curie, F-75231 Paris, France

The diffusive propagation of waves in disordered media may be significantly affected by interference effects such as coherent backscattering, weak and strong localization. Whereas these effects are relatively well understood in the case of linear media, the influence of nonlinearities on the interferential properties of multiple scattering has only started to be explored. In this talk, I report on our recent work [1] on coherent backscattering of light by cold atoms which, at higher intensities, become nonlinear due to the onset of saturation. Using a perturbative approach, valid for weakly nonlinear scatterers, I show that the nonlinearity has a fundamental impact on the phenomenon of coherent backscattering. In particular, nonlinear interference effects may lead to an enhancement of the backscattered intensity by more than a factor two.

[1] T. Wellens, B. Grémaud, D. Delande, and C. Miniatura, PRA 73 (2006, in press).