Enhancement of the stimulated Raman scattering of aqueous sulfuric acid solutions via cascaded resonance

Abstract

In the present study, we propose a scheme for generating multi-mode resonance-enhanced stimulated Raman scattering (SRS) of H2O in a low concentration (6.5 mol/L) sulfuric acid aqueous solution. The SRS of H2O exhibits a prominent vibrational feature peak at 3371 cm−1 and a secondary peak at 3325 cm−1. The closeness of the vibrational frequencies for the H–O stretching modes in different water structures allows for resonance interaction. The enhanced vibrational mode can serve as a “new starting point” for a cascaded resonance process, resulting in the generation of eight SRS Stokes signals with a normal distribution centered on the characteristic Raman peak at 3371 cm−1. This research holds potential implications for the development of multi-wavelength and significant frequency shift Raman lasers.