Green function approach to scattering of nonclassical light by bounded media

We show that using the properties of the photon Green's function one can successfully describe the propagation of arbitrary nonclassical optical radiation through structured materials. In contrast to the similar input-output approach, our method is not restricted neither to the spatial homogeneous matter nor to the specific direction of light beam incidence or outcoupling. Several quantum states of light are addressed in detail, such as Fock, Glauber, and different squeezed light states, and their Green functions are given. Furthermore, it is demonstrated how scattering of light at a slab can be described with Poynting's energy flow vector, and how experimental setups can be modeled.