Hyper spectral resolution stimulated Raman spectroscopy with amplified fs pulse bursts
Hongtao Hu, Tobias Flöry, Vinzenz Stummer, A. Pugžlys, Markus Kitzler-Zeiler, Xinhua Xie, А. М. Желтиков, Andrius Baltuška
Abstract
We present a novel approach for Stimulated Raman Scattering (SRS) spectroscopy in which a hyper spectral resolution and high-speed spectral acquisition are achieved by employing amplified offset-phase controlled fs-pulse bursts. We investigate the method by solving the coupled non-linear Schrödinger equations and validate it by numerically characterizing SRS in molecular nitrogen as a model compound. The spectral resolution of the method is found to be determined by the inverse product of the number of pulses in the burst and the intraburst pulse separation. The SRS spectrum is obtained through a motion-free scanning of the offset phase that results in a sweep of the Raman-shift frequency. Due to high spectral resolution and fast motion-free scanning the technique is beneficial for a number SRS-based applications such as gas sensing and chemical analysis.