Initial steps of supercontinuum generation in photonic crystal fibers

The onset of supercontinuum generation in a photonic crystal fiber is investigated experimentally and numerically as a function of pump wavelength and intensity with 100-fs pulses. Soliton formation is found to be the determining factor in the initial step. The formation and behavior of a blueshifted, nonsolitonic component, emitted as the soliton evolves towards the stable regime, is investigated and the role of phase matching through higher-order dispersion is highlighted. Good agreement between experiments and simulations is obtained.