Investigation of collisionally induced stimulated scattering in sodium vapor with temporal and spectral resolution

In this work we present fully time-resolved spectra of Amplified Spontaneous Emission (ASE) and Stimulated Raman Scattering (SRS) in sodium vapor. We observe that the ASE signal precedes the SRS emission, and the peak of the amplified Stokes pulse is delayed with respect to the peak of the laser pulse. The time evolution of the line widths of the ASE and Raman signals is also shown. We find that the line widths of the stimulated fluorescence component (ASE) and the stimulated Raman radiation change with time. Both spectra start as small narrow fluctuating lines, then the line widths reach maximum values and thereafter decrease with time.