Fig. 1. Schematic description of the different calculation steps of the genetic algorithm used in this work.

Fig. 2. (a) Chromatic dispersion curves calculated by GA routine for a three rings PCF. Red curves correspond to the chromatic dispersion for the best offspring at the first generation (empty circles) and at the thirteenth generation (empty squares) in the case of population B. Blue curves correspond to population A (filled circles for the first generation, and filled squares for the thirteenth). (b) Example of the three rings PCF used in the GA method (black is air and grey is silica).

Fig. 3. Blue curve: Chromatic dispersion as a function of wavelength calculated by GA routine for the 9 rings structure. The pitch Λ and the radius r are respectively equal to 2.35 μm and 0.33 μm. Black curve: chromatic dispersion obtained for a 9 ring structure with the following parameters: Λ = 2.59 μm and r = 0.29 μm, corresponding to ref. [4]. Inset: dashed green lines represent the dispersion curves for the minimum pitch and the maximum radius (upper curve) and for the minimum pitch and minimum radius (lower curve) authorized in the GA.