Efficient full-wave 3D and 2D waveguide eigenvalue analysis by using the direct FD-TD wave equation formulation

A modified finite-difference time-domain (FD-TD) formulation based on the direct discretization of the vector wave-equation is applied to the efficient analysis of hybrid-mode waveguiding structures. For both 3D and 2D waveguide eigenvalue problems, the FD-TD wave-equation formulation requires only one grid, and just the solution of three coupled equations is necessary. Numerical examples concerning the resonance frequencies for an inhomogeneously filled waveguide resonator as well as the fundamental- and higher-order mode propagation factors for insulated image guides, shielded coupled dielectric guides, and lateral open dielectric ridge guides demonstrate the efficiency of the method. The theory is verified by comparison with results obtained by other methods.<>