Evolutionary optimization of nanophotonic multilayered structures

Abstract

International audienceWe apply optimization algorithms inspired by evolution photonic structures. Trying to maximize the reflection coefficient of a multilayered structure systematically leads to the famous Bragg mirror. This shows it is an optimal structure and explains why it is often found in nature. Genetic algorithm Genetic/evolutionary algorithms are optimization algorithms directly inspired by evolution. They use a process of selecting structures (here each structure will be called an "individual") best suited to what is desired. A cost function is defined for this purpose. The lower it is, the more the structure/individual is considered adapted, and the higher are its chance to "survive". • We take a starting population that is randomly generated. • The next generation is produced using different ways • A part of the previous generation is selected and kept-the more fit the individuals, the higher their chances to be kept. • The rest of the next generation is obtained combining two parents that have been selected in the previous generation because they are adapted to our criteria. • The best individual is always kept, as a reference