The power coupling result from the FDE solver gives the fraction of the power which can couple from the beam to the fiber mode, so in order to get the power into the fiber you would multiply the power coupling by the power of the laser source that you would use in experiment.
You could also use the EME solver with two ports to calculate the S-parameters as you mentioned. To do this, you could set up 3 cell group regions with the fiber in the center cell and air in the cells on either side. You can then specify the Gaussian beam profile as the input and output port modes. The method for loading a custom field profile into a port can be found here:
If you wanted to use the same Gaussian beam profile generated using the FDE solver’s overlap analysis tool, it’s possible to save the generated beam profile data into the necessary .mat file format using code like the following:
# get data from d-card
x = getdata("gaussian1","x");
y = getdata("gaussian1","y");
z = getdata("gaussian1","z");
Ex = getdata("gaussian1","Ex");
Ey = getdata("gaussian1","Ey");
Ez = getdata("gaussian1","Ez");
Hx = getdata("gaussian1","Hx");
Hy = getdata("gaussian1","Hy");
Hz = getdata("gaussian1","Hz");
# create dataset
EM = rectilineardataset("EM fields",x,y,z);
# save dataset to .mat file which can be imported
After running the simulation and propagating the fields, you can get the S-parameters from the user s-matrix result of the EME solver.
Let me know if this sounds like what you’d like to simulate, and if you have further questions about the setup. It might look somewhat similar to the following example:
For the parameter sweep, you might look into how the parameter sweep is set up in this example:
In the example, the geometry is varied and the user s-matrix is collected. Then from the script the desired S-parameter elements are extracted from the user s-matrix.