Experimental and numerical study on chirped transient stimulated Raman scattering in dispersive medium

Experimental and numerical study on chirped transient stimulated Raman scattering in ethanol have been performed. Negatively chirped pump pulses yielded much higher conversion efficiency than positively chirped pump pulses. The calculated results reveal that the group velocity mismatch between the pump and Stokes pulses can rapidly degrade the conversion efficiency when the pump laser generates chirped pulses. However, the combined effects of group velocity dispersion and self-phase modulation offset the negative chirps during propagation, yielding higher conversion efficiency. This is a novel mechanism for controlling transient stimulated Raman scattering and is likely to be of importance for various applications.