Cavity-Polariton Effects in II-VI Microcavities

Semiconductor microcavities are monolithic multilayer heterostructures grown by molecular beam epitaxy. They allow the confinement along the growth axis of both photons between the Bragg reflectors and excitons in quantum wells. If the exciton-photon coupling matrix element is large enough compared to the line width, the system is said to be in the strong coupling regime. In that case a quantum well exciton couples to another discrete state: the photon mode of a planar microcavity with the same in-plane wave vector, to give rise to quasi-stationary states named cavity polaritons. In this regime, the Fermi golden rule does not hold any more and the optical properties, linear or nonlinear, are strongly related to polariton features. A review of the optical properties of CdTe-based microcavities operating in the strong coupling regime is given in this paper. The strength of the exciton-photon coupling, dynamic optical properties, and relaxation processes along polariton dispersion curves will be discussed, as well as stimulated emission of cavity polariton luminescence.