Cascaded amplification via three-beam double stimulated Raman scattering in benzene

Abstract

As stimulated Raman scattering (SRS) microscopy has emerged as a powerful tool for label-free imaging of biomolecules in biological systems, SRS has also received much attention in the field of nonlinear optics. Here, we enhanced the cascade SRS of benzene through an energy competition mechanism in the three-beam double SRS processes. A three-beam (pump, Stokes, and anti-Stokes beam) SRS scheme was formulated and demonstrated to simultaneously induce the parallel and cascaded SRS processes, which were related to the Raman active modes in the same molecule. Both two SRS processes generated high-order Stokes SRS through resonance enhancement of the double sample cell configuration, which effectively suppressed the CARS (Coherent anti-Stokes Raman Scattering) signal. It was shown in the experimental results that the cascaded SRS up to six orders from 562 to 780 nm were generated, and the SRS threshold of the multi-order Stokes components was lowered. The present work can potentially contribute to the development of super-resolution SRS microscopy.