Eigenmode analysis of anisotropic optical fibres or integrated optical waveguides

Using the finite-element technique, the eigenmodes propagating in an inhomogeneous, anisotropic optical waveguide with arbitrary cross-section are computed. The method is based on a variational principle for the modes of an anisotropic dielectric waveguide. It is shown that very accurate results are obtained, even for the guides formed by very small changes in the refractive index. As an example, the propagation characteristics of a channel guide embedded in LiNbO3 are computed.