Highly Nonlinear Fiber
  Broadest continuum is
generated by the fiber when the
ultrafast laser pulse is in the
anomalous dispersion region.
 The pulse intensity begins to
self Raman shift to longer
wavelengths.
 Due to break up of these
higher order solitons, four-wave
mixing generates frequencies
at wavelengths shorter than
zero dispersion  wavelength.
Aeff =13.9 mm2
Dispersion slope = 0.024 ps/(nm2 km)
Nonlinear coefficient g = 8.5 ( W km)-1
J. W. Nicholson et. al, Opt. Lett 28, 643, 2003