Abstract
We report on a comparison of free-space and cavity-enhanced Raman spectroscopy for gas-phase measurements of nitrogen and oxygen in ambient air. Real-time analysis capabilities and continuous Raman signals with low power diodes make the technique non-invasive, affordable, compact, and applicable for usage in non-reacting flows. We derive a comprehensive model for estimation of photon emission for both free-space and cavity-based signals and discuss trade-offs in how to organize the cavity geometry for maximum gain relative to free space. Measurements in both free and cavity configurations are compared to the expected signals, demonstrating the usefulness of the model in predicting amplification. The present results can serve as a quick guide on how to use low-power continuous wave lasers in a cavity setup to obtain enhanced laser-induced spontaneous Raman scattering.
© 2019 Optical Society of America
Full Article | PDF ArticleMore Like This
Pinyi Wang, Weigen Chen, Fu Wan, Jianxin Wang, and Jin Hu
Opt. Express 27(23) 33312-33325 (2019)
Faisal Nadeem, Julien Mandon, Simona M. Cristescu, Amir Khodabakhsh, and Frans J. M. Harren
OSA Continuum 2(9) 2667-2682 (2019)
Jinduo Wang, Jin Yu, Zeqiang Mo, Jianguo He, Shoujun Dai, Jingjing Meng, Yang Liu, Xue Zhang, and Hong Yi
Appl. Opt. 58(11) 2773-2781 (2019)