Analysis of optical waveguides and some discontinuity problems

Using the vector H-field finite element method, the authors obtain new results for the solution of diffused channel waveguides, the effect of electrodes and buffers for rib waveguides, and the calculation of coupling length for a directional coupler. They also present solutions of discontinuities for optical waveguides by combining the vector finite element method and least-square boundary residual methods. Some basic discontinuity steps, such as vertical misalignment, change of width, and change of rib height for rib waveguides are illustrated here