Theory of intermode scattering of electromagnetic waves in one-dimensionally inhomogeneous media and planar resonators with semitransparent walls

An analysis is made of the scattering of photons by random optical inhomogeneities of a medium. The probabilities of photon transitions to guided and undamped (in vacuum) steady-state modes are determined. Characteristics of undamped modes associated with semitransparent walls result in almost periodic peaked frequency and angular dependences of the intensity of the scattered light in vacuum. The results are used to explain the properties of the radiation emitted from a thin-film ZnS:Mn laser.