Genetic algorithms for reflective filters design

A genetic algorithm (GA) with adaptive mutations has been employed for the design of Bragg reflectors. The algorithm enables three different design types: (a) composition and thickness of each layer are optimized; (b) two compositions are chosen for the two alternating materials, and the thickness of each layer is optimized; (c) composition and thickness of two layers are chosen and the pair is repeated. The algorithm enables the finding of the optimal design for two chosen incident and final media, and it is capable of taking into account the existence of a finite optically thick substrate. The algorithm is very versatile and can be applied for the design of refractive filters using various materials. We have demonstrated application of this algorithm to the design of Al_xGa_1-xN reflectors, as well as organic and dielectric reflectors