Excitation of Guided Waves on a Lossless Dielectric Slab by an E-Polarized Complex Source Point Beam

A lossless slab excited by an E-polarized two-dimensional (2-D) complex source point (CSP) beam is studied analytically. Such a source, unlike a Gaussian beam, satisfies exactly the Helmholtz equation and radiation condition, without paraxial approximation or formulation incompleteness. The guided-waves fields as well as the scattered fields in the regions above and below the slab are determined; in turn, the corresponding powers are directly calculated. Numerical results on the variations of these quantities with respect to the slab electrical thickness, the beam angle of incidence, the source aperture size and location are presented. Substantial power transfer from the finite directive source into each of the slab's guided waves is recorded especially in the case of near-grazing beam illumination. Such a finding may inspire further theoretical and experimental efforts towards numerous research directions like non-invasive sensing, wireless optical tagging and energy teleportation.