Investigation of the contribution of the first excited and ground electronic states to stimulated resonance Raman scattering

In order to identify whether the stimulated resonance Raman scattering (STRRS) spectrum observed in a rhodamine 6G solution is attributable to scattering by vibrational levels of the first electronically excited state, a comparison was made between the STRRS spectra and the Raman spectrum of the ground electronic state obtained by inverse Raman scattering. The population of the electronic states was determined by measuring the bleaching curve under advanced STRRS conditions. Although a comparison of the frequencies did not reveal any significant discrepancy, it was shown that the scattering was predominantly due to the vibrational levels of the first electronically excited state. Investigations showed that a detailed analysis of the population conditions is required to identify the active levels in STRRS.