xopto.materials.ri.util.model.cauchy module¶

class Cauchy(params, pp: Optional[xopto.materials.ri.util.model.base.Scale] = None, **kwargs)[source]¶

Cauchy model of the refractive index.

$n^{2} = A_{1} + A_{2}\lambda^{2} + A_{3}/\lambda^{2} + A_{4}/\lambda^{4} + A_{5}/\lambda^{6} + A_6/\lambda^{8}$

Parameters

params (np.ndarray) – Default model parameters.
pp (xopto.materials.ri.util.model.base.Scale or xopto.materials.ri.util.model.base.Normalize) – Wavelength preprocessor instance.
kwargs (dict) – Parameters passed to the baseclass.

guess(wavelengths: numpy.ndarray, n: numpy.ndarray) → list[source]¶

Returns an initial guess of the model parameters for optimization/fit.

Parameters

wavelengths (np.ndarray) – The wavelengths of light at which the values of refractive index are defined.
n (np.ndarray) – The values of refractive index at the given wavelengths of light.

Returns

params0 – Initial guess for the values of the model parameters

Return type

np.ndarray

ri(params: numpy.ndarray, wavelengths: numpy.ndarray)[source]¶

Compute the refractive index for the given model parameters and wavelengths of light.

Parameters

Returns

n – Refractive index estimated for the given model parameters and at the given wavelengths of light.

Return type

np.ndarray