Help with Exporting To GDS - Lumerical Grating Coupler Example
I have run through the entire example of the inverse design of grating coupler 2D from https://support.lumerical.com/hc/en-us/articles/360042800573-Inverse-design-of-grating-coupler-2D-
I have modified the parameters for my own use. I have modified the model to create a fully etched geometry (the grating etches in the silicon device layer are the entire height of the layer, in this case 600nm). However when I export the design to GDS it does not create the proper GDS geometry in that it is not fully etched (eg. the etches should be empty space, not a polygon) as you can see from the screenshot below:
The etched regions seem to be being treated the same as the full height silicon device layer. I am not overly familiar with the GDS export fucntion, but in the example code given in the file pid_grating_coupler_3D.py from the link above the following code is given:
Can anyone help me how I can amend the code to create the proper GDS file for the fully etched gratings?