Continuous Wave Supercontinuum Generation Through Pumping in the Normal Dispersion Region for Spectral Flatness

We demonstrate the generation of a spectrally flat continuous wave supercontinuum by pumping deep in the normal dispersion region. A Raman cascade forms up to the anomalous dispersion region, where modulation instability supercontinuum dynamics are initiated. The Raman cascade seeds the frequency up-shifted part of the continuum, leading to a spectral flatness of 5 dB from 1.15 to 2.15.