A novel treatment of open dielectric waveguides

A general spectral-domain technique is developed which reduces the dimensionality of the space-domain integral equation for a large class of open dielectric waveguides. This technique has the merit of easy extension to three-dimensional structures. As an example, a simple rectangular slab guide is considered, and the corresponding spectral-domain modified Green´s function is derived. To solve the resulting equations, the method of moments is employed in the spectral domain using entire-domain Hermite-Gaussian functions. The results show good agreement with other methods, and only a few basis functions are needed to achieve quick convergence.<>