Background-free single-beam coherent Raman spectroscopy assisted by air lasing

We develop a background-free single-beam coherent Raman scattering technique enabling the high-sensitivity detection of greenhouse gases. In this scheme, Raman coherence prepared by a femtosecond laser is interrogated by self-generated narrowband air lasing, thus allowing single-beam measurements without complex pulse shaping. The unique temporal and spectral characteristics of air lasing are beneficial for improving the signal-to-noise ratio and spectral resolution of Raman signals. With this method, SF6 gas present at a concentration of 0.38% was detected in an SF6 -air mixture. This technique provides a simple and promising route for remote detection due to the low divergence of Raman signals and the availability of high-energy pump lasers, which may broaden the potential applications of air lasing. (C) 2022 Optical Society of America

Automated summary

The technique enables high-sensitivity detection of greenhouse gases by using air lasing to interrogate Raman coherence, improving signal-to-noise ratio and spectral resolution. It provides a simple and promising route for remote detection due to low divergence of Raman signals and high-energy pump lasers.