refind.n_group

refind.n_group(N, wl, *args)

Group velocity refractive index.

Parameters:

• N (func) – (Complex) Refractive index as function of wavelength and possible arguments: N(wl, args).
• wl (array) – Wavelenth axis in um (can also be a single float).
• args (mixed) – Variable number of arguments to be provided to N.

Returns:

Group velocity refractive index Ng = N - wl * dN with same shape as wl.