qspec.sellmeier  (  w ,  a ,  b  )[source]

The Sellmeier equation for calculating the refractive index of a material with the lists of coefficients a and b for the wavelength w $$ n = \sqrt{1 + \sum_i \frac{A_i\lambda^2}{\lambda^2 - B_i}}. $$

Parameters:

warray_like

The wavelength $\lambda$ (μm).

andarray | Iterable

A list of coefficients $A_i$.

bndarray | Iterable

A list of coefficients $B_i$ (μm).

Returns:

nndarray

The refractive index $n$.