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

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 al- lowed to have arbitrary orientation with respect to the layer geometry. First, the un- bounded 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 physi- cally meaningful and compact structure. A numerical example is provided where we have computed the reflectivities.