An integral-equation formulation is presented for the scattering (reflection, transmission, and radiation) of incident surface waves by a generally heterogeneous dielectric discontinuity located along an open-boundary dielectric waveguide of arbitrary cross-section shape. An equivalent-polarization description of the discontinuity region is proportional to the product of its electric field with the contrast of its refractive-index profile against that of the unperturbed waveguide. This equivalent polarization leads to an electric field integral equation that describes the unknown field induced in the discontinuity region. Scattering coefficients are subsequently calculated in terms of the induced electric field. Moment-method numerical solutions are implemented for slice discontinuities along a symmetric-slab waveguide.
© 1987 Optical Society of America
Thomas G. Livernois and Dennis P. Nyquist, "Integral-equation formulation for scattering by dielectric discontinuities along open-boundary dielectric waveguides," J. Opt. Soc. Am. A 4, 1289-1295 (1987)