Hi Dr. Popoff,
I have been trying to use the pyMMF module shared on your website for simulation of multimode fiber modes and am concerned about the appearance of the simulated modes for graded index fibers.
I used your code in Example 1 that you provide in the readme file on github. Additionally, for a comparison I also computed the modes for the same parameters using their Laguerre-Gauss (LG) polynomial approximations. I show in the attachment below three examples of LP modes (real part) simulated using the pyMMF module (top row) and the LG polynomial approximation of the same modes (second row). I was expecting to see similar results, but some of the modes simulated using pyMMF appear in a line or square geometry. Is this normal? I was expecting both LP modes and LG modes to have circular geometries and similar profiles.
Could you please throw some light on the difference between the two representations?
Thanks!