Derivative-free optimization for optical chirality enhancement

\nWe adopt a multi-objective optimization approach to design one-dimensional photonic crystals with large optical chirality enhancements. We show that this technique allows for a large design flexibility in terms of selected materials and operational wavelengths. Finally, we demonstrate that the designed platforms provide state of the art chirality enhancements above the two orders of magnitude over arbitrarily large areas and broad spectral ranges.\n