Accurate analysis of power coupling between two arbitrarily ended dielectric slab waveguides by the boundary-element method

The boundary integral equations that are called guided-mode extracted integral equations are applied to the investigation of the power-coupling-properties between two arbitrarily ended dielectric slab waveguides. The integral equations derived in this paper can be solved by the conventional boundary-element method. The reflection and coupling coefficients of the guided wave, as well as the scattering power, are calculated numerically for the case of incident TE guided-mode waves. The results presented are checked by the energy conservation law and the reciprocity theorem. Numerical results are presented for several geometries of coupling, including systems with three-layered symmetrical and asymmetrical slab waveguides.