SPONTANEOUS EMISSION IN A NONHOMOGENEOUS MEDIUM - DEFINITION OF AN EFFECTIVE POLARIZABILITY

The definition of an effective polarizability associated with a dipole transition is shown to result from the use of a dyadic Green's function in solving the electron equation of motion obtained from a classical model of spontaneous emission that takes into account the presence of nonhomogeneities in the electric permittivity. This polarizability provides access to the line shape associated with the transition; it also provides a generalized procedure for studying the effects of changes in the electromagnetic environment on line shapes, frequency shifts, and transition rates.