How to Build Your Circuit

1

Draw an arbitrary line path to add etch masks to, typically to create the ridge of a waveguide. 

This includes straight paths…
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…constant curvature bends or Euler bends…

3

…and offset paths described by an arbitrary function. In this case we’ve used an S bend.

4

‘Sub-Paths’ allow paths to be drawn relative to another for easier manipulation.

1

Turn paths into waveguides by first defining an epitaxy structure using the layers editor. 

Build your stack using the extensive material database or by adding your own materials.[continue to next slides]

2

Add etch masks to the path to define the waveguide ridge. Etch mask width can also be defined as a function to create tapered waveguides or to reduce loss in bends. A path may have multiple etch masks (for example to convert between shallow and deep etch waveguides).

3

Create a familiar ridge waveguide by choosing the depth of the etch. We can also introduce tilted sidewalls and corner rounding to simulate how devices can appear after fabrication.

1

The canvas must be split into computational regions suitable for EME. The ‘comp regions’ have two varieties:

• The path computational region conforms to the geometry of a path. The width of this region should be chosen following FIMMWAVE manual section 2.1.8 Optimising the Cross-Section Size to ensure simulation boundaries don’t affect results.
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• The spanning computational region allows the coupling between multiple waveguides, a box boundary similar to a FIMMPROP simulation. These regions should be only as large as when waveguides are coupled, where their path computational regions meet.

3

Waveguide coupling can be simulated using path computational regions when attaching to a sub-path. This allows coupling simulations and a conformal computational region.