Niklas Christian, Wackerbarth Hainer, Ctistis Georgios
Institut für Nanophotonik Göttingen e.V., Hans-Adolf-Krebs-Weg 1, 37077 Göttingen, Germany.
Sensors (Basel). 2021 Mar 2;21(5):1698. doi: 10.3390/s21051698.
The market of gas sensors is mainly governed by electrochemical, semiconductor, and non-dispersive infrared absorption (NDIR)-based optical sensors. Despite offering a wide range of detectable gases, unknown gas mixtures can be challenging to these sensor types, as appropriate combinations of sensors need to be chosen beforehand, also reducing cross-talk between them. As an optical alternative, Raman spectroscopy can be used, as, in principle, no prior knowledge is needed, covering nearly all gas compounds. Yet, it has the disadvantage of a low quantum yield through a low scattering cross section for gases. There have been various efforts to circumvent this issue by enhancing the Raman yield through different methods. For gases, in particular, cavity-enhanced Raman spectroscopy shows promising results. Here, cavities can be used to enhance the laser beam power, allowing higher laser beam-analyte interaction lengths, while also providing the opportunity to utilize lower cost equipment. In this work, we review cavity-enhanced Raman spectroscopy, particularly the general research interest into this topic, common setups, and already achieved resolutions.
气体传感器市场主要由基于电化学、半导体和非分散红外吸收（NDIR）的光学传感器主导。尽管这些传感器类型能够检测多种气体，但对于未知的气体混合物而言，它们可能具有挑战性，因为需要事先选择合适的传感器组合，同时还要减少它们之间的串扰。作为一种光学替代方法，可以使用拉曼光谱，因为原则上无需先验知识，它几乎可以涵盖所有气体化合物。然而，由于气体的散射截面较低，其量子产率也较低。人们已经通过不同方法提高拉曼产率来规避这一问题。特别是对于气体，腔增强拉曼光谱显示出了有前景的结果。在这里，腔可用于增强激光束功率，实现更长的激光束与分析物相互作用长度，同时也提供了使用成本更低设备的机会。在这项工作中，我们回顾腔增强拉曼光谱，特别是对该主题的总体研究兴趣、常见设置以及已实现的分辨率。
