Amplification of O-D stimulated Raman scattering in DMSO-D₂O solution via intense laser-driven electron transfer

In this study, we investigated in detail the regulation mechanism of electron transfer under laser-induced breakdown (LIB) on weak O-D stimulated Raman scattering (SRS) in DMSO-D₂O solutions. Significantly, the Raman activity of O-D vibrations was greatly enhanced by two orders of magnitude due to electron transfer in DMSO molecules. Density functional theory (DFT) calculations showed that the O-D Raman activity was significantly enhanced in the DMSO-D₂O dimer compared to the D₂O dimer. Additionally, the high-order (third-order) SRS peaks originating from the O-D vibration and the characteristic peaks representing the ice-like structure were detected, which were due to the Raman-enhanced four-wave mixing (FWM) process induced by the hydrated electron and intramolecular electron transfer. It was hoped that our results could provide a meaningful reference for the development of multi-wavelength and significant frequency-shifted Raman lasers.