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gdsfactory / gdsfactory-photonics-training

training for gdsfactory
https://gdsfactory.github.io/gdsfactory-photonics-training/
MIT License
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Issue on page /notebooks/20_modesolver_fem.html #37

Closed oz99 closed 19 hours ago

oz99 commented 22 hours ago

Is there a method of specifying the angle of the component edges from gdsfactory?

I'm using gdsfactory/FEMWELL to conduct mode simulations and the WG geometry returns an angled edge along the height of the structure when I haven't explicitly instructed this.

image

I specified the width of my straight WG to be 490nm. The width is 490nm at the center of the specified WG height. The bottom width of the WG is ~40nm larger while the top is around 40nm narrower. I also tried using a polygon with the same settings and this angle still appears.

I can only achieve a normal angled (90 deg) edge WG when defining the WG geometry purely in FEMWELL.

Is this a result of the GenericPDK layerstack?

Thanks, Oz

oz99 commented 21 hours ago

Update:

I don't believe this is a layerstack issue. When using the layerstack in the 3d viewer the structure has normal (90 deg) edges. I think this might be an issue with how \meshing within FEMWELL is inputting the component or layerstack. Will Link Issue to gplugins.

image

joamatab commented 20 hours ago

Hi Ozan,

If you'd prefer not to use the default generic PDK 10-degree sidewall angle in the layer stack, you can either create a customized layer stack or work directly with Femwell to define the angle you need.

oz99 commented 19 hours ago

Thanks for the quick reply Joaquin.

Looks like I will be creating a custom layer stack! :)

Ozan