High-Sensitivity Multitrace Gas Simultaneous Detection Based on an All-Optical Miniaturized Photoacoustic Sensor

作者：Guojie Wu, Zhenfeng Gong, Haie Li, Junsheng Ma, Ke Chen, Wei Bing Peng, Qingxu Yu, Liang Mei · 发表于：Analytical Chemistry · 年份：2022 · DOI：10.1021/acs.analchem.2c02767 · 被引用次数：48 · 研究领域：Spectroscopy and Laser Applications、Atmospheric Ozone and Climate、Atmospheric and Environmental Gas Dynamics

We propose an all-optical miniaturized multigas simultaneous detection photoacoustic (PA) sensor, which is primarily composed of a copper tube, a silica cantilever, and four single-mode fibers. Three single-mode fibers are used as excitation fibers to transmit lasers of different wavelengths, and the remaining one is used as a probe fiber. The volumes of the PA cell (PAC) and the sensor are 36 μL and 71 cubic millimeters, respectively. A laser photoacoustic spectroscopy (PAS) system, using the all-optical miniaturized PA sensor as a detector, 1532.8, 1576.3, and 1653.7 nm distributed feedback (DFB) lasers as the excitation sources for acetylene (C 2 H 2 ), hydrogen sulfide (H 2 S), and methane (CH 4 ) gases, and a high-speed spectrometer as a demodulator, has been developed for multigas simultaneous measurements. The minimum detection limits of 4.8, 162, and 16.6 parts per billion (ppb) have been achieved for C 2 H 2, H 2 S, and CH 4, respectively, with an integration time of 100 s. The reported sensor shows a potential for high-sensitivity multigas simultaneous measurements in cubic millimeter-scale space.