FEM Solver
A finite element mode solver
A finite element mode solver add-on for FIMMWAVE
The FEM Solver brings the finite-element method to FIMMWAVE and is offered as an optional add-on to the FIMMWAVE base module.
Using the FEM Solver you can automatically locate and analyse the eigenmodes of almost any waveguide supported by FIMMWAVE. The FEM Solver is ideal to solve complex waveguide geometries as its highly optimised mesh can adapt itself to virtually any arbitrary shape.
The FEM Solver features automatic mesh refinement techniques which allow it to increase the resolution exactly where it is needed, as shown in the picture above. This will allow you to obtain highly accurate results in a short amount of time.
It will model highly lossy materials and anisotropic materials and will do so rapidly and accurately.
The FEM Solver also supports fully arbitrary dielectric and permeability tensors, enabling the accurate modelling of optically active materials, biaxial materials at arbitrary orientation and magneto-optic materials; this allows the FEM to model optical isolators, PPLN and many others.
Features
- Real and complex versions
- Bend mode version (see an example here)
- Speed and accuracy enhanced for horizontally and/or vertically symmetric structures
- Full arbitrary permittivity and permeability tensors
- Fast: calculates many modes simultaneously
- Mode analysis tools - compute confinement factor, group index, dispersion etc, see utilities.
- First and second order elements
- High quality, fast fully automatic mesh generator optimised for electro-magnetic problems
- Automatic mesh refinement, allowing the solver to deal with high-index contrast, metal and small features very efficiently
The FEM Solver supports perfect electric wall and perfect magnetic wall boundary conditions, as well as perfectly matched layers (PMLs).
Structures for which the FEM Solver is recommended
- Circular or elliptical fibres, photonic-crystal fibres, polarisation maintaining fibers
- Waveguides with mixed geometries: rectangles, ellipses, polygons
- Waveguide with curved and/or slanted interfaces
- Waveguides with both large and very small features
Metallic structures
- Uniaxially and biaxially birefringent materials at arbitrary angles
- Optically active materials: optical isolators, Faraday rotators etc.
- Ferromagnetic, ferroelectric (e.g. PPLN) and magneto-optic materials
See also the Mode Solver Features Table for comparison with other solvers.