How can I improve the accuracy of the effective refractive index to more than ten decimal places?

[694856790]

I would like to use the radial function of pyMMF to solve the high-precision effective refractive index so that I can calculate the mode dispersion. As we all know, long-distance optical fiber is very sensitive to this, so I would like to ask how to improve the calculation accuracy. Thanks!

[wavefrontshaping]

Hi,

I would have to dig into the code to check where the type of float variable is set and if the computation is compatible with better accuracies.

But before going there, what type of precision do you need? float64? float128? On which solver?

Then, the precision is not only fixed on the refractive index data, but also on the convergence criteria you chose (and depends also on the solver, I will assume it is the radial one).
Look at the API reference, you can, for instance, change the default tolerance for the field (to consider that the field is 0 at long distances from the core for guided modes).