Ma Hanxu, Chen Yanjun, Qiao Shunda, He Ying, 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 Jan 6;42:100683. doi: 10.1016/j.pacs.2025.100683. eCollection 2025 Apr.
A high sensitive methane (CH) sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) using self-designed trapezoidal-head quartz tuning fork (QTF) and high power diode laser is reported for the first time in this paper. The trapezoidal-head QTF with low resonant frequency ( ) of ∼ 9 kHz, serves as the detection element, enabling longer energy accumulation times. A diode laser with an output power of 10 mW is utilized as the excitation source. A Raman fiber amplifier (RFA) is employed to boost the diode laser power to 300 mW to increase the excitation intensity. Acoustic micro-resonators (AmRs) are designed and placed on both sides of the QTF to form an acoustic standing wave cavity, which increases the acoustic wave intensity and enhances the vibration amplitude of the QTF. Additionally, the long-term stability is analyzed by Allan deviation analysis. When the average time of the sensor system is increased to 150 s, the minimum detection limit (MDL) of the CH-QEPAS sensor system can be improved to 15.5 ppb.
本文首次报道了一种基于石英增强光声光谱（QEPAS）的高灵敏度甲烷（CH）传感器，该传感器使用自行设计的梯形头石英音叉（QTF）和高功率二极管激光器。具有约9 kHz低谐振频率（ ）的梯形头QTF用作检测元件，可实现更长的能量积累时间。使用输出功率为10 mW的二极管激光器作为激发源。采用拉曼光纤放大器（RFA）将二极管激光器功率提升至300 mW，以增加激发强度。设计了声学微谐振器（AmR）并将其放置在QTF两侧，以形成声学驻波腔，这增加了声波强度并增强了QTF的振动幅度。此外，通过阿伦偏差分析对长期稳定性进行了分析。当传感器系统的平均时间增加到150 s时，CH-QEPAS传感器系统的最低检测限（MDL）可提高到15.5 ppb。
