Finite-element solution of anisotropic waveguides with arbitrary tensor permittivity

An improved vector finite-element method has been used for the solution of general anisotropic waveguide problems. This method is formulated in terms of all three components of the magnetic field and is valid for arbitrary tensor permittivity. In the improved finite-element analysis, the spurious nonphysical solutions do not appear when the effective refractive index is larger than 1. Therefore, this method is very useful for the analysis of the surface-wave modes of optical waveguides. To show the validity and usefulness of the improved finite-element method, computed results are illustrated for anisotropic rectangular waveguides with optic axis in any orientation and gyrotropic rectangular waveguides.