We report the observation of Raman solitons on numerical simulations of
transient stimulated Raman scattering (TSRS) with small group velocity
dispersion. The theory proceeds with the inverse scattering transform (IST) for
initial-boundary value problems and it is shown that the explicit theoretical
solution obtained by IST for a semi-infinite medium fits strikingly well the
numerical solution for a finite medium. We understand this from the rapid
decrease of the medium dynamical variable (the potential of the scattering
theory). The spectral transform reflection coefficient can be computed directly
from the values of the input and output fields and this allows to see the
generation of the Raman solitons from the numerical solution. We confirm the
presence of these nonlinear modes in the medium dynamical variable by the use
of a discrete spectral analysis.Comment: LaTex file, to appear in Inverse Problem