Write the response. Read the following conversation:
 - Can you explain the difficulties in creating a supercontinuum?
 - It is possible to create supercontinua in the normal region and in fact many of the early results discussed in the historical overview were pumped in the normal dispersion regime.
 - Are there any other interesting aspects about this article?
 - If the input pulses are short enough then self-phase modulation can lead to significant broadening which is temporally coherent.
 - What broaderening occurs?
 - However, if the pulses are not ultra-short then stimulated-Raman scattering tends to dominate and typically a series of cascaded discrete Stokes lines will appear until the zero dispersion wavelength is reached.
 - What happens at zero dispersion?
 - At this point a soliton Raman continuum may form.
 - Is it possible to superimpose the two?
 - 
As pumping in the anomalous is much more efficient for continuum generation, the majority of modern sources avoiding pumping in the normal dispersion regime.