|M.Sc Thesis||Department of Physics|
|Supervisor:||Prof. Akkermans Eric|
|Full Thesis text|
Coherent backscattering is an interference phenomenon which appears in disordered systems with time reversal symmetry. When illuminating such a medium with a monochromatic wave, the intensity returned from the bulk after multiple scattering, is found to be doubled in the backscattered direction with respect to the prediction of a theory which does not take into consideration interference effects. This increase in the scattered intensity apparently violates energy conservation. In this work we consider a semi infinite geometry and a weakly disordered medium, which is characterized by a dimensionless parameter kl0 which is much greater than 1, where k is the wave number of an incoming wave and l0 is the free mean path, i.e. the average distance between successive scatterings. A perturbation theory was written for the scalar wave version of this problem which explains the doubled intensity. Later it was shown that the violation of energy conservation can also be solved by this theory. We extend the theory to show that it satisfies energy conservation for polarized waves as well.