Abstract

Using the Green function method of quantisation of radiation in the presence of dielectric bodies and performing a generalised mode expansion of the vector potential, the problem of propagation of quantised radiation through dispersive and absorbing multilayer dielectric barriers is studied. The dielectric barrier structure is described in terms of a multistep (spatially varying) complex permittivity in the frequency domain, which is only required to satisfy the Kramers-Kronig relations, because of causality. The advantage of the method is that it enables one to obtain quantum input-output relations that do not only apply to regions of frequency far from the medium resonances, but they are valid, within the frame of linear electrodynamics, in the whole frequency domain.

© 1996 Optical Society of America