Stimulated Raman Transfer of SIT Solitons
  We treat theoretically the two-pulse plane-wave propagation problem associated with the stimulated Raman process. A strong pump pulse and a weak probe pulse interact self-consistently during mutual propagation through a medium in the three-level lambda configuration. We treat the pulse interaction fully coherently, but take initially incoherent mixed ground states to describe the medium. We present analytic pulse envelope solutions to the nonlinear evolution equations, and then test them numerically. We show that the entire process can be interpreted consistently as a three-regime evolution, in which the first and last regimes display behavior quantitatively the same as self-induced transparency. They are connected through a Raman transfer process in the intermediate regime. 
B.D. Clader and J.H. Eberly