Transmission of a Gaussian beam into a biaxial crystal

We derive integral representations that are suitable for studying the transmission of an electromagnetic Gaussian beam through a plane interface that lies between an isotropic medium and a biaxially anisotropic crystal for the case in which the interface normal is along one of the principal axes of the crystal. To that end, we use recently developed exact solutions for the transmitted fields to derive explicit expressions for the corresponding dyadic Green's functions as well as integral representations that are suitable for asymptotic analysis and efficient numerical evaluation.