Current limiting effects on laser compression by resonant backward Raman   scattering
  Through resonant backward Raman scattering, the plasma wave mediates the energy transfer between long pump and short seed laser pulses. These mediation can result in pulse compression at extraordinarily high powers. However, both the overall efficiency of the energy transfer and the duration of the amplified pulse depend upon the persistence of the plasma wave excitation. At least with respect to the recent state-of-the-art experiments, it is possible to deduce that at present the experimentally realized efficiency of the amplifier is likely constrained mainly by two effects, namely the pump chirp and the plasma wave wavebreaking. 
Nikolai A. Yampolsky and Nathaniel J. Fisch
physics.plasm-ph