Define a material with refractive index as a function of wavelength

[Ali ElrashedyParticipant]

Hi

I want to define an extra layer in optigrating which the refractive index is changing with wavelength (Gold).
There is anyway to do it.

[Steve DodsParticipant]

in OptiGrating, the refractive index can be a function of wavelength, the software already expects Sellmeier formulas. The problem with gold is the actual value of the refractive index. Fibres with gold will not be accurately modelled by LP modes. OptiGrating uses only LP modes, therefore one cannot expect accurate modelling of gratings in fibres made with gold in OptiGrating.