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A powerful waveguide mode solver

Modes of Diffused Waveguides

Simulation of Ti-diffused, Ge-diffused and ion-exchange with FIMMWAVE software

FIMMWAVE can efficiently model waveguides generated by diffusion processes. It can for instance calculate the modes of Ti:LiNbO3 waveguides in which Titanium is diffused in a Lithium Niobate substrate, of Ge:Si waveguides in which Germanium is diffused in a Silicon substrate, or ion-exchange glass waveguides. Such waveguides are widely used in electro-optic devices.

You can conveniently define diffused refractive index profiles in FIMMWAVE by several means, for example:

- by specifying the size and position of a diffusion source plus a diffusion length,
- by defining a Gaussian and erf profile,
- by importing an arbitrary profile from your own file.

Diffused Ti:LiNbO3 refractive index profile
Refractive index profile for a Ti:LiNbO3 waveguide designed in FIMMWAVE

The FDM Solver is ideal for finding modes of diffused waveguides thanks to its fine mesh which can readily render the diffused profiles with a resolution of a few nanometers.

Diffused Ti:LiNbO3 refractive index profile
Fundamental TE-like mode of a Ti:LiNbO3 waveguide