Coherent Raman comb generation in H2O2aqueous solutions by crossing-pump stimulated Raman scattering

The cascaded stimulated Raman scattering (SRS) of 30% H2O2 aqueous solutions was investigated using a pulsed Nd: YAG laser with a wavelength of 532 nm. The transfer of excess electrons between H2O2 and H2O molecules enhanced the SRS. Together, the decomposition of H2O2 and the intense SRS Stokes led to the generation of the crossing-pump effect of H2O2 aqueous solutions and the appearance of a new peak at 4229 cm(-1) that is excited by Stokes as the pump source. Crossing-pump not only reduced the threshold but also generated the broadband-coherent Raman comb, defined as a coherent radiation wavelength ranging from 434 to 831 nm (i.e., a Raman shift ranging from -4225 to 6756 cm(-1)). The anti-Stokes SRS was attributed to the four-wave mixing (FWM) process. (C) 2022 Optica Publishing Group