Gaussian Beam Interaction with a Planar Dielectric Interface

The problem of electromagnetic Gaussian beam scattering from a planar interface separating two lossless dielectric media is considered. Employing a modal plane wave expansion and the continuity of the fields across the boundary, the reflected and transmitted beams are obtained using the Fresnel approximation, and a Taylor series expansion of the reflection and transmission coefficients, for both polarizations. Particular emphasis is given to the beam shift of both the reflected and refracted beams, the change in width of the transmitted beam, and the behavior at polarizing incidence.