Get source frequencies at given wavenumber

[berzoll]

Hello,

I am trying to see which frequency my source is set at when I initialise it with eig_match_freq=False and I specify a kpoint.
The value that I am looking at is printed in the console at the beginning of the simulation (e.g. MPB solved for frequency_1(1.5,0,0) = 0.653985 after 18 iters, however I do not understand how to retrieve this within simulation. Also I am ideally interested in knowing the frequencies of n eigenmodes (e.g. the first 3), and not only the one of the eigenmode I set to source at.

Another confusing point is that the frequency found by MPB is different for the source solved within MEEP and by having the same cross-section defined directly in MPB. The eig_resolution value is set to an identical value, but to make the two converge I somehow have to significantly increase the MEEP resolution, and I do not understand why this parameter would have an impact on the eigenmodes found at the 2D source?