This User-Defined Surface DLL provides a realistic model of relief-type diffractive lenses based on zone-decomposition. Using zone-decomposition, diffraction into multiple orders can be accurately considered at once, and this method inherently accounts for wavelength dispersion and diffraction efficiency by modelling the actual shape of the diffractive element.
Application examples include the creation of advanced intraocular lens models, where the different orders are designed to provide sharp vision for multiple viewing distances, thereby substituting accommodation of the natural crystalline lens.
This application is discussed in detail in the following knowledgebase article:
Realistic modeling of relief-type diffractive intraocular lenses using User-Defined Surface DLLs – Knowledgebase (zemax.com)