Quantum well excitonic polaritons : coupling of quantum well excitons to electromagnetic waveguide modes

Abstract
The calculated dispersion curves of excitonic polaritons in GaAs quantum wells provide up to now not even a qualitative explanation for the time-of-flight experiments by Ogawa et al. [Phys. Rev. Lett. 64, 796 (1990)] which clearly show the existence of a mode with photon-like dispersion above the excitonic resonance. We show that this discrepancy can be removed by realizing that the QW constitutes a dielectric waveguide. The solution of the coupled system consisting of the exciton and the electromagnetic waveguide eigenmodes yields a drastically modified dispersion for the T and Z polariton as compared to previous calculations.