Ma Guosheng, He Yabai, Chen Bing, Deng Hao, Liu Ying, Wang Xingping, Zhao Zhihao, Kan Ruifeng
Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei 230031, China.
Graduate School of Science Island Branch, University of Science and Technology of China, Hefei 230026, China.
Sensors (Basel). 2021 Nov 17;21(22):7622. doi: 10.3390/s21227622.
We developed a cavity ringdown spectrometer by utilizing a step-scanning and dithering method for matching laser wavelengths to optical resonances of an optical cavity. Our approach is capable of working with two and more lasers for quasi-simultaneous measurements of multiple gas species. The developed system was tested with two lasers operating around 1654 nm and 1658 nm for spectral detections of CH and its isotope CH in air, respectively. The ringdown time of the empty cavity was about 340 µs. The achieved high detection sensitivity of a noise-equivalent absorption coefficient was 2.8 × 10 cm Hz or 1 × 10 cm by averaging for 30 s. The uncertainty of the high precision determination of δ13CH4 in air is about 1.3‰. Such a system will be useful for future applications such as environmental monitoring.
我们通过利用一种步进扫描和抖动方法来使激光波长与光学腔的光学共振相匹配，从而开发了一种光腔衰荡光谱仪。我们的方法能够使用两台及更多台激光器来对多种气体物种进行准同时测量。所开发的系统使用了两台分别在1654纳米和1658纳米附近工作的激光器进行测试，以分别对空气中的CH及其同位素CH进行光谱检测。空腔的衰荡时间约为340微秒。通过30秒的平均测量，实现的噪声等效吸收系数的高检测灵敏度为2.8×10厘米赫兹或1×10厘米。空气中δ13CH4高精度测定的不确定度约为1.3‰。这样的系统将对诸如环境监测等未来应用有用。
