Optimization of microstructured fibers with germanium-doped core for broad normal dispersion range

Abstract We have numerically studied different designs of technologically feasible microstructured fibers with a germanium-doped core in order to obtain normal dispersion reaching possibly far in the mid infrared. Hexagonal, Kagome and the combination of both geometries were numerically examined with respect to different constructional parameters like pitch distance, filling factor of air holes, number of layers surrounding the core, and level of germanium doping in the core. Our analysis showed that the broadest range of normal dispersion reaching 2.81 μm, while keeping an effective mode area smaller than 30 μm 2 , was achieved for a hexagonal lattice and a 40 mol% GeO 2 doped core. The proposed fibers designs can be used in generation of a normal dispersion supercontinuum reaching the mid-IR region.