Sometimes it is necessary to create User Defined surfaces to accurately model an optical system. Below are shown three such surfaces one a Radial Basis Function surface, a collection of micro-prisms and a superposition of cosine terms.
Sinusoidal surface used to model mid spatial frequency error .
Micro Prism Surface
2-D Cross-section of Sinusoidal Surface
Radial Basis Surface
Optical Engineering & Analysis LLC
OEA wrote surface fitting routines in MATLAB for translating deformations to optical surfaces provided by FEA modeling into parameters used in ZEMAX and FRED.
Fit surface (A) from FEA is translated into a surface sag (B) in Zemax EE before deformation (C) is compared to EE after deformation (D)