Accurate finite element software for microwave and optical waveguides

For rapid and accurate analysis of microwave and optical waveguides, users need a CAD-oriented interface to the underlying method. The authors describe an accurate method based on Berk's (1956) powerful variational result for resonators and waveguides. Particular attention is given to the user interface, whose role is to protect everyday users from all contact with the lengthy mathematical and numerical solution details connected with this or similar formulae. In the current package called POMME (Program for Optical and Microwave Modal Evaluation), the first steps are to input the cross-section of a particular waveguide on the graphics workstation and to give the material properties in each subregion. General-purpose automatic mesh-generation software is used to split the subregions into small finite elements where the unknown H field components are represented by linear combinations of first order shape functions. The fields at all the nodes can finally be obtained by solving a large (but sparse) global matrix problem.