Obtaining S-parameters - simulation results without full ModalComponentModeler data

[kalosu]

Hi there friends from the Tidy3D community,

I have followed the example in https://www.flexcompute.com/tidy3d/examples/notebooks/SMatrix/ to compute the S-parameters of a multiplexer structure that I am modelling using FDTD. I set my geometry externally via a STL file, parse it into tidy3D compatibile objects, decalre my input and output ports and finally use the ModalComponentModeler interface (as in the example) to wrap the whole simulation object and perform the S-parameters computations on top.

So in general it seems that the simulation works out, but once I try to get the data back into my local PC, I get a big file with a size larger than 1 GB.

I then try to load this data into a ModalComponentModelerData object but the loading/parsing process takes some time. Interestingly, from the documentation I see that this object also includes information on the original simulation domain. (Would this be the cause for such a big file in my results?)

Ultimately I want to have the data in a lightway manner. I just care about the S parameter results (I have 4 inputs with 1 mode and one output with 10 modes; I dont care about the modal cross-sections, just need the S parameters).

What could I do in this case? Is there any possible way to get only the S-parameters results instead of the full data blocks?

[momchil-flex]

Hello! If you're following this example as is, note that the base simulation contains a field monitor "domain_monitor", which spans the whole domain in a 2D cross-section. This is almost certainly the reason for the large data you are seeing. If you remove the monitor from the base sim as you only care about the s-matrix, the output data should be very small. Alternatively if you want to keep some field monitoring, selecting a smaller region and/or using interval_space for some down-sampling would help.