Phase quasi-integral for stimulated Raman scattering initiated by quantum fluctuation: experimental manifestation in statistics of soliton-like random pulses in a depleted pump

The phase quasi-integral for stimulated Raman scattering (SRS) is found-the relative phase of laser, stocks and polarization waves is nearly conserved during their propagation in Raman media. Due to this quasi-integral the temporal statistics of soliton-like pulses in a depleted pump are defined by phase statistics in the linear stage of SRS. Experimental results on the soliton-like pulse statistics are obtained confirming the existence of the phase quasi-integral.