FIMMWAVE

The Fiber Mode Solvers (Cylindrical Solvers)

Calculate the modes of any arbitrary single-mode or multi-mode circular fibre!

FIMMWAVE offers a large range of mode solvers for optical fibers. These fibers solvers take advantage of the cylindrical symmetry of your refractive index profile, and can therefore calculate the modes of optical fibres much faster and much more efficiently than a solver in Cartesian co-ordinates.

FIMMWAVE's fiber solvers can model single-mode and multi-mode fibers of arbitrary cylindrical geometry, including step-index and graded-index profiles, and even metallic fibers.

The Cylindrical Solvers module includes two fully vectorial fibers solvers, the General Fiber Solver and the Finite-Difference Fiber Solver, allowing you to check your results with two independent methods. You can find examples of mode calculations with the Cylindrical Solvers here. Applications in FIMMPROP include tapered fibers, lensed fibers, fiber Bragg gratings and metal-coated fibers.

Diverse fibre mode profiles calculated using the vectorial General Fibre Solver.

Fiber profiles of all kinds (stepped, graded etc.) can be easily created in FIMMWAVE's dedicated fiber editor, where they can also be imported from text files.

General Fiber Solver (optional module: Cylindrical Solvers)

This fully vectorial solver can solve generic circular waveguides with arbitrary non-absorbing refractive index. The solver is semi-analytical and very fast. It supports metallic or transparent boundaries.
A scalar version is also included.

Features:
Fully-vectorial and fast scalar versions
Supports perfect electric wall and perfect magnetic wall boundary conditions and Transparent boundary conditions. 
Mode analysis tools  - compute confinement factor, group index, dispersion etc, see utilities.

Finite-Difference Fiber Solver (optional module: Cylindrical Solvers)

Solves an arbitrary circularly symmetric refractive index waveguide using a finite difference algorithm in a cylindrical coordinate system for speed; supports absorbing materials including metals; leaky modes; PMLs. This is our most flexible and powerful cylindrical solver.

Features:
Perfectly Matching Layers (PMLs)
Loss, gain, leaky modes
Metal clad fibers
Fully-vectorial and fast scalar versions
Supports perfect electric wall and perfect magnetic wall boundary conditions, Transparent boundary conditions
Mode analysis tools  - compute confinement factor, group index, dispersion etc, see utilities.

Gaussian Mode Fiber Solver (included in Base Module)

This is a quick utility for getting the fundamental mode using the Gaussian approximation. The user simply specifies the effective index and the spot size of the desired mode - useful where the fiber profile is not known.

Features:
Mode analysis tools  - compute confinement factor, group index, dispersion etc, see utilities.

Single Mode Fiber Solver (included in Base Module)

This Solver will compute the fundamental mode of a single-mode step index fiber, given core index, cladding index and core diameter.

Features:
Mode analysis tools  - compute confinement factor, group index, dispersion etc, see utilities.

See also the Mode Solver Features Table for comparison with other solvers.

Structures for which the Fiber Solvers are recommended:

Any structure with a circular symmetry. Non-cylindrical fibers (e.g. PCFs) can be modelled with FIMMWAVE's FEM and FDM Solvers.