Sun Haiyue, He Ying, Qiao Shunda, Zhang Chu, Ma Yufei
National Key Laboratory of Laser Spatial Information, Harbin Institute of Technology, Harbin 150000, China.
Zhengzhou Research Institute, Harbin Institute of Technology, Zhengzhou 450000, China.
Photoacoustics. 2025 Feb 11;42:100699. doi: 10.1016/j.pacs.2025.100699. eCollection 2025 Apr.
This paper presented a highly sensitive light-induced thermoelastic spectroscopy (LITES) sensor for detecting hydrogen sulfide (H₂S) gas. Optical path multiplexing (OPM) technology was implemented within the fiber-coupled multi-pass cell (MPC) to realize ∼ 80 m gas absorption optical path length (OPL), compensating the weak absorption coefficient of HS in the near-infrared band. A circle-head quartz tuning fork (QTF) with resonant frequency of ∼ 9.5 kHz was adopted in the H₂S-LITES sensor to enhance the energy accumulation time and the detection ability. Compared with commercial QTF, signal-to-noise ratio (SNR) based on circle-head QTF was improved by a factor of 3.36 times. Minimum detection limit (MDL) for HS detection was measured to be 238.8 ppb. When the integration time of the system was increased to 250 s, the MDL could be improved to 19.8 ppb.
本文提出了一种用于检测硫化氢(H₂S)气体的高灵敏度光致热弹性光谱(LITES)传感器。在光纤耦合多程池(MPC)中采用了光路复用(OPM)技术,以实现约80米的气体吸收光程长度(OPL),补偿H₂S在近红外波段较弱的吸收系数。H₂S-LITES传感器采用了谐振频率约为9.5kHz的圆头石英音叉(QTF),以延长能量积累时间并提高检测能力。与商用QTF相比,基于圆头QTF的信噪比(SNR)提高了3.36倍。测得H₂S检测的最低检测限(MDL)为238.8 ppb。当系统的积分时间增加到250秒时,MDL可提高到19.8 ppb。