Mode solver

A mode solver is a numerical tool that determines the electromagnetic field distribution and the effective refractive index (propagation constant) of the modes guided by an optical waveguide.

How does a mode solver work?

For a given waveguide cross-section (geometry and refractive-index distribution of the materials), the solver solves the wave equations using the finite element method (FEM) or finite difference method (FDM), returning the field profiles of the guided modes and their effective refractive indices. This result is a key input for further BPM simulations or coupling calculations between waveguides.

Applications

Mode solvers are used in designing single-mode and multi-mode waveguides, analyzing propagation losses, designing waveguide polarizers, and choosing waveguide geometry for the required modal dispersion.

Related terms

Optical waveguide

FEM in optics

BPM