even_aspheric_surface_sag

hcipy.optics.even_aspheric_surface_sag(radius_of_curvature, conic_constant=0, aspheric_coefficients=None)

Makes a Field generator for the surface sag of an even aspherical surface.

The surface profile is defined as:

\[z = \frac{cr^2}{1 + \sqrt{1-\left(1+k\right)c^2r^2}} + \sum_i=0 a_i r^{2i+4}\]

With z the surface sag, c the curvature, k the conic constant and \(a_i\) the even aspheric coefficients.

It is important to note that this definition deviates from the Zemax definition of an even aspheric surface. In Zemax the 2nd order term is also included in the expansion, which is unnessary because the conic surface itself already accounts for the 2nd order term.

Parameters

radius_of_curvaturescalar

The radius of curvature of the surface.

conic_constantscalar

The conic constant of the surface

aspheric_coefficientsarray_like

Contains the high-order even aspheric coefficients.

Returns

Field generator

This function can be evaluated on a grid to get the sag profile.