Refinement is performed by optimizing the merit function with respect to the layer thicknesses. You can select optimization method which suits your problem best. Optimization methods used by OptiLayer provide rapid convergence of the optimization procedure.

The goal of refinement and synthesis procedures is to design optical coatings with desired spectral (angular) characteristics. For this purpose, a set of construction parameters, the number of layers, the materials they are made of and their thicknesses, are varied to optimize a merit function. Refinement modes of OptiLayer utilize the most powerful first, second, and higher order optimization routines:

quarter wave mirrorDesign of High Reflector: Starting design - Quarter wave mirror
high reflector high reflective coating
Spectral performances of two design solutions (high reflectors) obtained from the same starting design by two different optimization methods (Newton method and DLS method)