Vectorial eigenmode solver for bent waveguides based on mode matching

Vectorial eigenmode solver for circularly bent dielectric waveguides is described. The approach is strictly analogous to the well-known film mode-matching method for straight waveguides. Accurate calculation of radiation loss is enabled by leaving the calculation window open in the radial direction. In order to increase numerical stability and accuracy, a new computer code was written for cylindrical functions of complex order and argument. A high-contrast bent rib guide is used for comparison of results with a commercial mode solver.