Unusable layout_waveguide2 inside PCell environment.

[Paudet-ul]

Hello!

It would be nice to be able to use layout_waveguide2 inside the PCell environment without having to use a defined waveguide type in the .xml. For example, we might want to define an arbitrary cross-section and use the parameters in the layout_waveguide2 function in SiEPIC.utils.layout to extrude this cross-section.

The issue with the function seems to be that it requires the layer textual name, while in the PCell environment, we're getting a Layer Info. Looking into the KLayout doc, it is possible to add a name as an attribute to the layer info object, but by default this is not done in the code.

Adding the layer name in the layer info objects would make layout_waveguide2 usage more flexible and usable in the PCell environment. I try adding it on line 333 in SiEPIC.utils.init_.py. This fixes the issue when creating my PCell in a script. But, when I try to add the cell manually inside KLayout, the Layer Info still have an empty name. I'm unsure how to propose an official fix for this issue, and would request help on the matter, especially to make it work in the GUI PCell interface.

I think it can bring much more flexibility to be able to extrude a path with cross-sections defined in code.