Dipole lifetime in stratified media

The field of an electric dipole inside an arbitrary system of parallel slabs is evaluated with a Green´s function approach. Application of boundary conditions yields a matrix formalism that allows compact formulation of the problem. The method is extended to the general case of parallel stratified medialike cavities containing a dipole. Effects on spontaneous-emission rate of dipole emitters are evaluated and discussed for different types of planar microcavities.