Stimulated Raman scattering signal amplification in ethanol molecules via resonant cascading

Applied Physics Letters, Volume 118, Issue 12, March 2021. Lowering threshold and enhancing intensity of stimulated Raman scattering (SRS) have been a major focus of nonlinear optics. In our experiments, we combined SRS generation and amplification techniques to enhance the SRS signal. The amplification was achieved through a process called resonance effect, where the frequency difference between the pump laser and the Stokes light emitted from the working medium had self-matched with the vibrational energy level. The performance improvements included a higher SRS conversion efficiency, reaching up to 5.31%, approximately three times the value of a single sample cell efficiency of 1.739%, and realization of a cascaded SRS up to four orders extending from 461 to 997 nm. These Stokes and anti-Stokes coherent lights were generated coaxially to the pump beam as axial and conical ring beams, respectively, which can be explained by the four-wave mixing. This technique has the potential to contribute to the development of a multi-wavelength cascade Raman laser.