esis.optics.num_interpolation

esis.optics.num_interpolation = 32

The number of nodes used to interpolate the response of each multilayer coating, and of the sensor, over the angle of incidence.

Solving the transfer matrices of a stack costs far more than the raytrace it belongs to, and the response is smooth in the angle of incidence, over which each ESIS surface spans only a few degrees. Interpolating it reproduces the exact solve to better than a part in \(10^5\) while making optika.systems.SequentialSystem.linearize() about two and a half times faster; the sensor, whose absorbance is the response of its oxide over its substrate, cost as much again as the two mirrors together until it was interpolated too.

See optika.materials.multilayer_efficiency(). Set to None to solve every ray exactly, which is worth doing when checking a change to the optical model.