Reply To: Waveguide Cross-section and Mode Solver

[Ronald]

Dear Heiner,

Good to hear Nazca helps you with your work.

You certainly have a relevant question on xsections and index models. Nazca has functionality to define the geometrical cross-sectional structure of a waveguide and connect it to a modesolver, e.g. for obtaining the Neff of modes, precisely as in your questions. The package demofab inside Nazca does contain examples of two rib-style xsections in file pdk_15_technology.py.

This so far has been based on a simple symmetric slab solver, ridge stacks and the effective index method (EIM). This early xsection and solver implementation was mainly done to play with Nazca’s internal architecture and user syntax, and explore possible paths to connect that to mask layout for later development.

Over the last year or so we have been (and are) upgrading as intended this waveguide cross-sectional geometry and index calculation architecture to be able to connect it to basically any solver with at least a command-line interface on board or, alternatively, a mathematical model of your waveguide index. As this topic has been considered a beta feature there are no tutorials on it. It actually may not work as intended in the last few releases.

In summary, it would require a few months of patience to have this updated index model and solver handling available in the public Nazca release. If it moves to the release state there will also be a tutorial on it.

Ronald