Application of frequency-locking cavity-enhanced spectroscopy for highly sensitive gas sensing: a review

Abstract

Spectroscopic gas sensing technologies based on absorption and Raman scattering are fast, nondestructive, long-term stable and highly selective. By making use of an optically resonant cavity, the sensitivity can be enhanced hundreds to thousands of times. However, frequency-locking technology is necessary to maintain a stable resonant condition. In this review, various applications of Pound-Drever-Hall (PDH) and optical feedback (OF) frequency-locking cavity-enhanced spectroscopy (cavity ring-down spectroscopy, cavity-enhanced absorption spectroscopy and cavity-enhanced Raman spectroscopy) for highly sensitive gas sensing are presented. The effect of frequency-locking cavity-enhanced spectroscopy for improving the sensitivity of gas sensing is demonstrated. In addition, the key parameters and advantages as well as limitations of different frequency-locking cavity-enhanced spectroscopy are summarized and discussed.

Keywords:

• gas sensing
• frequency-locking technology
• optical resonance cavity
• cavity-enhanced spectroscopy

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported and funded by the National Natural Science Foundation of China (U1766217, 61605020) and the Open Foundation of National Engineering Laboratory for Ultra High Voltage Engineering Technology（Kunming, Guangzhou）(NEL202011). Pro. Andrew Orr-Ewing from University of Bristol was greatly appreciated for revision to this work.