SPONTANEOUS EMISSION IN THE PRESENCE OF A DIELECTRIC SLAB

The spontaneous emission of photons by an atom placed near the dielect ric slab is analyzed using global free electromagnetic modes, satisfyi ng necessary continuity conditions at the slab boundaries. These modes include the modes extended over the whole space (traveling) and the m odes trapped to a waveguide formed by the slab (trapped). To describe angular properties of spontaneous emission a parametrization of the tr aveling modes by the outgoing waves has been proposed. Angular charact eristics of the traveling photon emission, distributions of the trappe d photon emission, as well as global decay rates have been calculated using the quantum approach and standard perturbation theory. Enhanceme nt and suppression of radiative decay rates in various configurations have been shown. A certain calculational error in an earlier paper by Khosravi and Loudon [Proc. R. Soc. London Ser. A 438, 373 (1992)] affe cting thin slabs and results near waveguide-mode thresholds has been i mproved.