中国物理B ›› 2023, Vol. 32 ›› Issue (10): 104209-104209.doi: 10.1088/1674-1056/acdac1

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Simultaneous detection of CH4 and CO2 through dual modulation off-axis integrated cavity output spectroscopy

Yi-Xuan Liu(刘艺璇), Zhou-Bing Wang(王周兵), Xin-Xin Wei(韦欣欣), Jing-Jing Wang(王静静), Xin Meng(孟鑫), and Gui-Lin Mao(毛桂林)   

  1. School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
  • 收稿日期:2023-03-30 修回日期:2023-05-16 接受日期:2023-06-02 出版日期:2023-09-21 发布日期:2023-10-08
  • 通讯作者: Jing-Jing Wang, Gui-Lin Mao E-mail:jin16217@mail.ustc.edu.cn;maoguilin@jsnu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 62005108 and 62205134), the National Key Research and Development Program of China (Grant No. 2022YFC2807701), and the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province, China (Grant Nos. 20KJB140009 and 21KJB140008).

Simultaneous detection of CH4 and CO2 through dual modulation off-axis integrated cavity output spectroscopy

Yi-Xuan Liu(刘艺璇), Zhou-Bing Wang(王周兵), Xin-Xin Wei(韦欣欣), Jing-Jing Wang(王静静), Xin Meng(孟鑫), and Gui-Lin Mao(毛桂林)   

  1. School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
  • Received:2023-03-30 Revised:2023-05-16 Accepted:2023-06-02 Online:2023-09-21 Published:2023-10-08
  • Contact: Jing-Jing Wang, Gui-Lin Mao E-mail:jin16217@mail.ustc.edu.cn;maoguilin@jsnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 62005108 and 62205134), the National Key Research and Development Program of China (Grant No. 2022YFC2807701), and the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province, China (Grant Nos. 20KJB140009 and 21KJB140008).

摘要: This study established a novel method for the simultaneous detection of two-component gases. Radio frequency (RF) white noise disturbance laser current and wavelength modulation were simultaneously used to improve the off-axis integrated cavity output spectroscopy technique, and a high-precision dual modulation OA-ICOS (RF-WM-OA-ICOS) system was established. The two laser beams were coupled into one laser beam that was applied incident to the cavity of RF-WM-OA-ICOS system. The second harmonic signals of CH$_{4}$ and CO$_{2}$ gas simultaneously appeared in the rising or falling edge of a triangular wave. This method was used to measure CH$_{4}$ and CO$_{2}$ with different concentrations. The results indicated that the proposed system has high stability and can accurately and simultaneously measure the concentrations of CH$_{4}$ and CO$_{2}$, with an optimal integration time of 220 s. The minimum detection limit was 10 ppb for CH$_{4}$ and 1.5 ppm for CO$_{2}$. The corresponding noise equivalent absorption sensitivity values were calculated as $2.67 \times 10^{-13}$ cm$^{-1}\cdot$Hz$^{-1/2}$ and $5.18 \times 10^{-11}$ cm$^{-1}\cdot$Hz$^{-1/2}$, respectively. The proposed dual-component gas simultaneous detection method can also be used for high-precision simultaneous detection of other gases. Therefore, this study may serve as a reference for developing portable multicomponent gas analyzers.

关键词: off-axis integrated cavity output spectroscopy, wavelength modulation, radio frequency (RF) white noise, simultaneous detection

Abstract: This study established a novel method for the simultaneous detection of two-component gases. Radio frequency (RF) white noise disturbance laser current and wavelength modulation were simultaneously used to improve the off-axis integrated cavity output spectroscopy technique, and a high-precision dual modulation OA-ICOS (RF-WM-OA-ICOS) system was established. The two laser beams were coupled into one laser beam that was applied incident to the cavity of RF-WM-OA-ICOS system. The second harmonic signals of CH$_{4}$ and CO$_{2}$ gas simultaneously appeared in the rising or falling edge of a triangular wave. This method was used to measure CH$_{4}$ and CO$_{2}$ with different concentrations. The results indicated that the proposed system has high stability and can accurately and simultaneously measure the concentrations of CH$_{4}$ and CO$_{2}$, with an optimal integration time of 220 s. The minimum detection limit was 10 ppb for CH$_{4}$ and 1.5 ppm for CO$_{2}$. The corresponding noise equivalent absorption sensitivity values were calculated as $2.67 \times 10^{-13}$ cm$^{-1}\cdot$Hz$^{-1/2}$ and $5.18 \times 10^{-11}$ cm$^{-1}\cdot$Hz$^{-1/2}$, respectively. The proposed dual-component gas simultaneous detection method can also be used for high-precision simultaneous detection of other gases. Therefore, this study may serve as a reference for developing portable multicomponent gas analyzers.

Key words: off-axis integrated cavity output spectroscopy, wavelength modulation, radio frequency (RF) white noise, simultaneous detection

中图分类号:  (Spectral absorption by atmospheric gases)

  • 42.68.Ca
07.88.+y (Instruments for environmental pollution measurements) 42.62.Fi (Laser spectroscopy) 95.85.Jq (Near infrared (0.75-3 μm))