Boundary problems for polariton propagation in thin layers and quantum wells

Summary We show how to compute the optical functions (reflection and transmission) of a semiconductor thin slab, in the vicinity of nearly degenerate exciton states. Additional boundary conditions are not required in the coherentwave-function approach and multiple-polariton effects are included since Maxwell equations are satisfied. When the slab thickness is comparable to the exciton Bohr radius, centre of mass quantization results. When the slab thickness is smaller than the Bohr radius, we obtain, quantum well polaritons. Numerical examples appropriate to GaAs are given.