adding SiN crossing to PDK

[felme1]

No description provided.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 73.68%. Comparing base (8b959f9) to head (7cf53fc).
Report is 5 commits behind head on master.

Additional details and impacted files

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  Coverage   73.68%   73.68%           
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  Files          96       96           
  Lines       11804    11804           
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  Hits         8698     8698           
  Misses       3106     3106           

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[lukasc-ubc]

Thank you very much for your contribution!

Here are suggestions to further improve the performance.

1. I suspect your taper is not adiabatic and introduces loss. You could use a smooth taper that doesn't have abrupt transitions. There is a PCell in the EBeam-Beta library. I overlaid it on your cell for illustration purposes.

2. The straight regions leading into the middle of the crossing don't do anything. You can reduce their lengths to 0.

Perhaps you could run the simulation on this design and compare to yours? Then maybe investigate the taper_bezier parameters, primarily lengths, but potentially the the two a, b, bezier parameters.

Also, did you use 3D-FDTD for your simulation, or 2D? (hopefully 3D).

thanks!

crossing_SiN_1550.gds.zip