Optimization of dispersions in GeO2 doped photonic crystal fibers with square lattice

Germanium doped photonic crystal fibers with differences in the layers' air hole diameters in the cladding are presented to obtain flat dispersion, small effective mode area, and low attenuation property for supercontinuum generation applications. The flatness and small value of the dispersion depend on the lattice geometry when the fibers have the same germanium doping concentration.