THEORY OF POLARITON PHOTOLUMINESCENCE IN ARBITRARY SEMICONDUCTOR MICROCAVITY STRUCTURES

A quantum theory of quantum well polaritons in semiconductor microcavi ties is developed. The model takes into account the coupling between t he exciton level and the structured continuum of electromagnetic modes relative to the particular geometry of the microcavity. A general equ ation for the polariton dispersion is obtained as a function of the ca vity and exciton parameters. The equation is valid in both weak and st rong coupling regimes and reproduces the existing measurements of micr ocavity polariton dispersion. A model for the polariton luminescence i s then derived from the theory. It is possible to define a polariton d ecay rate only when the resonances in the polariton density of states can be considered as quasimodes. The two limiting cases of very weak a nd very strong coupling regimes are consequently identified. In these cases the polariton radiative probabilities are derived for light emit ted on the left and right sides of the microcavity separately. The inf luence of the microcavity structure on the polariton dispersion and ra diative rates is discussed and in particular the role of the microcavi ty leaky modes is described in detail. A discussion of the luminescenc e mechanism in the intermediate coupling case is also presented.