Inhomogeneous Refinement procedure starts with a single layer of a specified thickness and with some refractive index and extinction coefficient.  A number of subdivisions (steps) of the initial single layer into thin layers of equal initial thickness is also specified.

At the first stage of the Inhomogeneous Refinement  refractive indices and thicknesses of thin layers are varying in order to optimize the merit function.

At the second stage, the obtained inhomogeneous design is converted to a multilayer stack consisting of materials, loaded to memory. The converted design is re-optimized at this stage if necessary. The final design is automatically exported to OptiLayer and can be used for further processing, for example, with the help of the Needle Optimization procedure.