Enhanced resonant backscattering of light from quantum-well excitons

The angle-dependent resonant Rayleigh scattering of light from excitons in a disordered quantum well is studied theoretically. An enhancement of the s cattered intensity peaked on the backscattering direction is predicted, for values of the parameters corresponding to realistic GaAs/AlGaAs heterostru ctures. It is shown that this effect can be isolated by measuring the diffe rential enhancement between two different scattering directions. An analysi s in terms of perturbation theory provides a simple analytical approximatio n of the measurable quantity.