Dyadic Green's functions for a two-layer biaxially anisotropic medium

Abstract

The dyadic Green's functions (DGF's) of a two-layer biaxially anisotropic medium are derived. The principal coordinate system of the anisotropic medium is allowed to have arbitrary orientation with respect to the layer geometry. First, the unbounded DGF is derived using the Fourier transform method. Hence the DGF's for the two-layer medium in the spectral domain are formulated. Using a matrix method the coefficients of the two-layer DGF's are expressed in terms of half-space Fresnel reflection and transmission coefficients. To complete this procedure the various relevant half-space Fresnel coefficients are derived. The form in which the results are presented has a physically meaningful and compact structure. A numerical example is provided where we have computed the reflectivities.