Düsseldorf 2007 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 15: Nichtlineare optische Effekte und Lichtquellen III
Q 15.6: Vortrag
Montag, 19. März 2007, 17:45–18:00, 5J
Weak localisation of light in disordered nonlinear media — •Thomas Wellens1 and Benoit Gremaud2 — 1Institut für Theoretische Physik, Universität Erlangen-Nürnberg, Staudtstr. 7, 91058 Erlangen — 2Laboratoire Kastler Brossel, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05
In general, transport of waves in disordered media cannot fully be described as a simple diffusion process, since interference effects lead to a reduction or even complete suppression of the diffusion constant (weak or strong localisation) and the appearance of a coherent backscattering peak.
On the present poster, we examine the impact of nonlinearities on the interferential corrections to the diffusive transport. Using diagrammatic methods in combination with a dilute medium approximation, we derive equations describing the coherent transport of the average wave intensity in the nonlinear medium. In the case where the wave intensity is conserved, we predict an effective dephasing mechanism induced by the nonlinearity, which reduces the height of the coherent backscattering peak. The opposite occurs for amplifying media, where coherent backscattering factors larger than the linear barrier two can be observed.