Dear Ahmad,
Thank you for your response. I have indeed modelled the geometry using the OptiFiber software, and the resulting effective indices agree with the plot in the article at https://optiwave.com/optifiber-manuals/optical-fiber-fiber-mode-solvers/” (namely, about 1.45495).
However, for my thesis, I am more interested in the mathematics rather than a simulation. Therefore, I tried using the formulas from the linked article to calculate the index, but this does not result in that same value of 1.45495. This means that either my implementation is incorrect (which I’ve double-checked using that Mathematica file) or there is a mistake in the OptiWave support article.
Do you happen to know if there is indeed a mistake?
With kind regards,
Tommie