Long wavelength extension of CW-pumped supercontinuum through soliton-dispersive wave interactions

A supercontinuum spanning over 700 nm with an average spectral power of 1.7 mW/nm and flatness of 6 dB was produced in a solid core, double zero dispersion wavelength photonic crystal fiber pumped with a high power, continuous-wave ytterbium fiber laser. The spectrum displays a strong feature centered around 1980 nm. Through numerical simulations we demonstrate that this feature is initially generated through the shedding of Cherenkov radiation by solitons at the second zero dispersion wavelength, and then extended by a four-wave mixing process between this generated dispersive component and other solitons forming the continuum.