Elastic Scattering of Exciton Polaritons by Neutral Impurities

Abstract
A model based on the elastic scattering of exciton polaritons from residual neutral impurities is proposed to account for the line shape of the exciton-polariton photoluminescence emission in GaAs at low temperatures. The good agreement obtained with experimental spectra emphasizes the importance of impurity scattering on exciton-polariton transport for modes in the vicinity of the exciton energy. This model is applicable to any solid possessing dipole-active excitons.