We cut out the
spectral regions (from red to blue side of the spectrum) in order to identify
the frequency-time correspondence of the field intensity profiles.
There is the following order in the spectral domain (from red to blue side):
1) smooth spike belonging to the dispersive wave radiated by the strongest soliton;
2) slightly modulated spike belonging to the dispersive wave radiated by the weaker soliton;
3) modulated spectrum of this soliton;
4) remainder of the pump pulse (in the time domain it co-propagates with the dispersive wave from the second soliton), which would produce the third (weakest) soliton during the further propagation;
5) wide spectrum of the strongest soliton.