The behavior of the dispersion curves of quasidipole mode of anisotropic waveguide studied by semianalytical finite element method

In this study, repulsion of phase-velocity dispersion curves of quasidipole eigenmodes of waveguides with elliptic cross section in non-axisymmetric anisotropic medium is investigated. The modeling done by the semianalytical finite element technique reveals that in the vicinity of the near-crossover point the dispersion curves repulse rather than cross. The repulsion is accompanied by the rotation of the polarization of two quasidipole modes with frequency. The reason for such a behavior is the lack of symmetry in the model. The crossing is possible only in the models with the exact symmetry. Proposed scenario is important for geophysical problems, because it is the alternative to the well-known stress-induced anisotropy crossing of the dispersion curves.