Thin-film coatings design using second-order optimization methods

Abstract

Second order optimization methods such as the Newton-type methods are known to be extremely effective in solving various inverse and synthesis problems. Despite this they were not used for thin film optical coating design. The reason is a great difficulty in Hesse matrix calculation. We have found a mathematically strict approach increasing the performance of Hesse matrix calculation many times. It allows us to use various second order optimization methods in our new design program called OptiLayer. On the other hand, specific optimization methods based on the optimal control theory results were used to enhance the program efficiency. As a result a very powerful tool for optimal coatings design was received. The developed software allows the user to design complicated optical coatings consisting of many layers (up to several tens) and possessing non-standard spectral properties. The software easily allows the user to take into account various feasibility demands.