Can't reproduce dispersion curves

Hi, I’m trying to calculate dispersion curves for various waveguides, but no matter which materials or geometries I use I’m unable to reproduce the results from the papers I compare with. The results I’m comparing with are both experimental and computational. I’ve made sure through the material explorer that the refractive index function is the same as in the papers and I’ve tried to increase the mesh resolution. There’s no general pattern to how the dispersion changes. The maximum anomalous dispersion point will be at the wrong wavelength and have the wrong value, and the zero-dispersion points can deviate by more than 100 nm. Thank you in advance.

hi martinussen which materia system are you using? if you change the tolerance in material checking system from 0.1 ----->to 0.01 in (Si and SiO2 system) you will get I guess. let me your comment after checking this…

Hi Nanda,
I’m using Si3N4 on SiO2 and Si on SiO2 systems. Right now I’m trying to reproduce the results from this paper:
I’ve set the tolerance to 0.01 as you recommended and the fit looks good. I’m expecting to see zero dispersion around 1250 nm and 1520 nm, but instead I’m getting it at 1040 and 1620.