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flaport / meow

https://flaport.github.io/meow
Apache License 2.0
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documentation suggestions #40

Closed lukasc-ubc closed 3 weeks ago

lukasc-ubc commented 3 months ago

Hello Floris,

I could not find anywhere in the documentation where to set the wavelength for the simulations. I am guessing it has a default somewhere of 1.55 µm? In the example, I see "wl=1.55".

The example https://flaport.github.io/meow/examples/02_taper_length_sweep.html calls tqdm, which is undefined: for cs in tqdm(css):

adding from tqdm import tqdm helps.

It would be helpful to describe the S-matrix format, e.g., top left quadrant is the back-reflection, top right is the transmission. Use abs(S1[num_modes][0]) to find the transmission amplitude for the fundamental mode.

jan-david-fischbach commented 4 weeks ago

Hey @lukasc-ubc,

please excuse the slightly late reply. Thanks a lot for the helpful comments!

1. Wavelength

The vacuum wavelength is set in the meow.Environment that has to be provided when converting a cell to a cross section From the quick start guide:

  1. Cross Sections A Cell contains all the Structure info, but does not take any Environment information (such as temparature or wavelength) into account. This information is important as it influences the refractive index of the CrossSection.

which is then set as 

env = mw.Environment(wl=1.55, T=25.0)

I hope this is clear enough?

2. tqdm

In the generated html all imports at the beginning of the notebook are hidden. If you use the rocket icon to launch an interactive session (i.e. in colab: https://colab.research.google.com/github/flaport/meow/blob/main/examples/02_taper_length_sweep.ipynb) these imports (including tqdm) should be present. How did you run the notebook on your end?

3. Documentation of the S-matrix layout

I'll add the following description in the quick-start guide:

The resulting S-matrix has is formated such that S[0][0] is the complex reflection coefficient from the fundamental mode into the backwards propagating fundamental mode. S[num_modes][0] is the transmission from the fundamental mode into the fundamental mode, following the pattern S[<to_port>][<from_port>]. The mapping from ports to indices is provided in port_map.

I hope this will help Thanks again for the feedback Regards JD