We show that solitarylike stimulated Raman excitations are possible in mass
ive wavelength-division multiplexed fiber-optic systems. These self-similar
states can propagate across channels at a constant rate that depends on th
e total power launched in the system and the wave's spectral width. The evo
lution of these excitations under the action of noise and during collisions
is investigated in detail. (C) 1999 Optical Society of America.