EXCITON-POLARITONS IN HALF-SPACE

A rigorous method is presented describing the coupling between an exciton polariton in a halfspace semiconductor and the external driving field. The method is based on density matrix theory. It allows to consider realistic electron-hole interactions, spatial dispersion and extrinsic surface potentials. Without invoking additional boundary conditions or an artificial subdivision of the semiconductor it is shown that the influence of the surface can be isolated from the bulk behaviour. This is accomplished by a symmetric continuation of the restricted configuration space to bulk geometry inspired by the image source method in electrostatics. As a demonstration the solution is worked out for a simplified polariton model. The results are compared with other theories and with experimental reflection spectra.