DFT monitor records data for specified wavelength. The data is a mixture of all modes that were excited during the propagation. So the monitor might not be a good way to get the result.
I would suggest to usemode source and mode expansion monitor to get mode profile and S parameter or a or b coefficient to calculate mode amplitude.
Note 1 : If there is propagation and waveguide changes, the field profile is not a single mode. mode expansion monitor or port should be used to decompose the monitor data
Note 2: FDE also produce nomalized results if cross section of waveguide is uniform. But in your simulation its not the case.
Hope this helps.
Please Login to Report Topic
Please Login to Share Feed