uploading CPO heat example

[FilipeFcp]

I believe the results look like the paper, although I had to make some guesses on the material properties and heat power.
@momchil-flex, feel free to take a look if you are interested.

[github-actions]

Spell Check Report

CPOHeat.ipynb:

Cell 1, Line 1: 'co-packaged'
  > # Steady-state and transient thermal analysis for co-packaged optics
Cell 29, Line 16: 'lightgreen'
  > Ax[0].plot(np.log10(time_steps), temp3.values.squeeze(), color="lightgreen", label="ASIC left edge")
Cell 29, Line 28: 'lightgreen'
  > Ax[1].scatter(100, 0, color="lightgreen", s=50, marker="x")
Cell 45, Line 3: 'microrings'
  > This analysis is important for understanding thermal crosstalk between adjacent devices and for defining the requirements for stabilization and control loops that keep the microrings properly tuned.

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Checked 1 notebook(s). Found spelling errors in 1 file(s).
Generated by GitHub Action run: https://github.com/flexcompute/tidy3d-notebooks/actions/runs/18017479746

[tomflexcompute]

Great result @FilipeFcp and showcase of transient thermal analysis!

1. I suggest a more formal title such as "Steady-state and transient thermal analysis for co-packaged optics"

2. Since there are quite a lot of warnings, explain why they are and why it's fine to ignore in this case?

3. In the temperature plot, plot the structure boundaries as well?

[tomflexcompute]

Also tagging @prashkh since he is interested in this model as well.

[momchil-flex]

Looks great and seems to match the paper reasonably well! I wonder if the difference could be coming from the insulating BCs along x and y, in reality there's probably some heat going out of there too?

Just one note: the schematic appears on the top of the first cell but at the end of that cell it says "A schematic of the simulated structure can be seen in the image below:"

Just out of curiosity I noted that the meshing and solver seem to take about the same time ~25 minutes each. Hopefully we'll improve on the meshing side!

[momchil-flex]

Isn't the usual policy for one notebook to go in one place only?

I'm not necessarily opposed to linking in multiple places just wondering.

[alec-flexcompute]

Excellent work as always @FilipeFcp! A couple suggestions:

1. You might want to define the unstructured mesh in terms of one of the feature variables. Raw numbers might be more unclear as to why they were chosen.

2. For the two time_specs, you might want to deifne the time_step and total-time_steps variables at the beginning of cell 71 to have it match cell 79

[marc-flex]

Thanks @FilipeFcp. This is an awesome notebook!

Is it possible to use MultiPhysicsMedium instead of Medium to run this notebook? I feel like it would make sense to use it.

[prashkh]

Very nice notebook! I am sure a lot of people will be interested in this work. Thanks @FilipeFcp !!

[FilipeFcp]

Thanks everyone for the comments. Sorry, it took me a while to implement; I was running some mesh tests, and the 2D transient simulation takes quite a long time to run.

With a coarser mesh, the 2D transient simulation shows some strange dips, so I kept the first one.

@momchil-flex, these are the boundaries that they report in the paper. I think the discrepancies are in the source definition. They won't report in volumetric power, and I didn't find it in the paper any information to directly translate it.