Measurement of methane concentration with wide dynamic range using heterodyne phase-sensitive dispersion spectroscopy
-
摘要:目的
为实现痕量甲烷气体的宽动态范围高灵敏度检测，本文发展了双边带拍频抑制模式的外差相敏色散光谱技术，探索了电光调制器工作特性以及偏置电压调控方法，对比了抑制与非抑制模式下的色散相位谱轮廓与信噪比，并对检测性能(如线性动态检测范围)进行了系统研究。
方法基于近红外分布式反馈激光器和电光调制器，搭建了外差相敏色散甲烷气体检测系统，通过探索和分析电光调制器的最佳工作区间，实现了双边带拍频抑制进而得到了大幅值、高信噪比的色散相位信号。测量了典型高频(1.2 GHz)强度调制下甲烷/氮气标气的色散相位信号，获取了色散相位信号峰峰值随气体浓度变化规律。同时开展了波长调制光谱技术实验，对两种技术的线性度，检测动态范围和对光功率波动的抗干扰性能进行对比研究。最后，通过测量不同浓度的标气验证了该系统在宽动态，快速时间响应下的性能。
结果所开发基于外差相敏色散光谱技术的甲烷检测系统具有线性度高(
R 2 = 0.9999)，检测动态范围宽(38.5 ppm~40%)，且对光功率波动免疫性高的显著优势。结论本文研发的基于外差相敏色散光谱技术的气体检测技术在宽动态范围检测和实际现场检测应用领域具有广阔的前景。
Abstract:ObjectiveThis paper describes the development of dual-sideband beat-suppressed heterodyne phase-sensitive dispersive spectroscopy (HPSDS) for sensitive detection of trace gases across a wide dynamic range, explores the operational characteristics of the electro-optic modulator, and explores bias voltage control methods under sideband suppression mode. The dispersion phase spectral profiles and the corresponding signal-to-noise ratios in both suppression and non-suppression modes were compared before a comprehensive evaluation of the detection performance.
MethodAn HPSDS-based detection system was developed based on a near-infrared distributed feedback laser and an electro-optic modulator (EOM). The suppression of the dual-sideband beat was achieved by exploring and analyzing the optimal operational range of the EOM, leading to the optimization of dispersion phase signals with increased amplitude and high signal-to-noise ratio. The dispersion phase signals under typical high-frequency (1.2 GHz) intensity modulation were recorded for different standard methane/nitrogen mixtures. The relationship between the peak-to-peak values of the dispersion phase signals and the varied gas concentrations was then summarized. Meanwhile, wavelength modulation spectroscopy (WMS) experiments were conducted; subsequently, the HPSDS and WMS techniques’ performances were compared in terms of linearity, detection dynamic range, and immunity to optical power fluctuations; finally, the HPSDS-based system's performance was validated under a wide dynamic range and rapid time response was verified by measuring different concentrations of standard gases.
ResultExperimental results indicate that the HPSDS technique exhibits high linearity (
R 2 = 0.9999), a wide dynamic range (38.5 ppm to 40%), and remarkable immunity to optical power fluctuations.ConclusionThe dual-sideband-beat-suppression-HPSDS-based methane sensor developed in this study shows great potential for uses involving wide dynamic range detection and on-site practical trace gas detection.
-
图 1 两个1倍频拍频信号的矢量和信号的相位φ
Figure 1. The phase φ of the vector sum of two beat note signals with a frequency of ωm.
图 2 34.5 °C下激光器波长、功率与电流的关系
Figure 2. Laser wavelength and output power as a function of drive current at 34.5 °C
图 3 基于双边带拍频抑制模式HPSDS技术的CH4检测系统示意图
Figure 3. Schematic diagram of CH4 detection system based on dual-sideband beat-suppressed HPSDS
图 4 (a)实验测得的EOM输出光功率与其偏置电压的关系；(b)调制频率为1200 MHz，在抑制模式与非抑制模式下测得的10% CH4的色散相位信号(T = 298 K, P = 1 atm, L = 20 cm)；(c)双边带拍频抑制后的拍频信号频谱图；(d)无双边带拍频抑制时的拍频信号频谱图
Figure 4. (a) The measured output power of EOM as a function of bias voltages; (b) Measured dispersion phase signals of 10% CH4 with or without dual-sideband beat suppression at the modulation frequency of 1200 MHz (T = 298 K, P = 1 atm, L = 20 cm); (c) The frequency spectrum of the beat note signal with suppression of dual-sideband beat; (d) The frequency spectrum of the beat note signal without suppression of dual-sideband beat
图 5 (a) 不同CH4浓度下测得的色散相位信号；(b) HPSDS信号峰峰值随CH4浓度的变化关系
Figure 5. (a) Measured dispersion phase signals at different CH4 concentrations; (b) Peak-to-peak values of HPSDS signals as a function of CH4 concentration
图 6 (a)不同CH4浓度下的HPSDS峰峰值、WMS-2f和WMS-2f/1f信号值; (b) 0.1%~0.8%浓度范围内的WMS-2f , WMS-2f/1f信号值-浓度线性关系
Figure 6. (a) HPSDS peak values, WMS-2f and WMS-2f/1f signals at different CH4 concentrations; (b) Linear relationship between WMS-2f, WMS-2f/1f signals and concentration within the range of 0.1% to 0.8% CH4, respectively
图 7 (a) 15分钟连续测量10% CH4的结果浓度分布图；(b) 测量结果的频率分布直方图及高斯曲线拟合曲线；(c) HPSDS，WMS-2f和WMS-2f/1f 信号的Allan方差分析
Figure 7. (a) Diagram of concentration distribution results for continuous measurement of 10% CH4 for 15 minutes; (b) Frequency distribution of the measured concentration and the Gaussian profile fitting; (c) Allan deviation analysis of HPSDS, WMS-2f and WMS-2f/1f signals
图 8 连续监测下CH4浓度随时间的变化结果
Figure 8. Results of continuous monitoring of CH4 in the gas flow
-
[1] FAROOQ A, ALQUAITY A B S, RAZA M, et al. Laser sensors for energy systems and process industries: perspectives and directions[J]. Progress in Energy and Combustion Science, 2022, 91: 100997. doi: 10.1016/j.pecs.2022.100997 [2] 王倩, 蔡伟伟, 陶波. 基于层析成像的激光强度分布测量方法[J]. 中国光学,2023,16(4):743-752. doi: 10.37188/CO.2022-0016WANG Q, CAI W W, TAO B. Laser intensity distribution measurement method based on tomographic imaging[J]. Chinese Optics, 2023, 16(4): 743-752. (in Chinese). doi: 10.37188/CO.2022-0016 [3] 任颐杰, 颜昌翔, 徐嘉蔚. 增强吸收光谱技术的研究进展及展望[J]. 中国光学,2023,2023,16(6):1273-1292.REN Y J, YAN CH X, XU J W. Development and prospects of enhanced absorption spectroscopy[J]. Chinese Optics, 2023, 2023,16(6): 1273-1292. (in Chinese). [4] 刘成员, 于江玉, 李奉翠, 等. 拉曼光谱测试技术在可充电铝离子电池储能机理的研究进展[J]. 应用化学,2023,40(10):1347-1358.LIU CH Y, YU J Y, LI F C, et al. Research progress of Raman spectroscopy technique in energy storage mechanism of rechargeable aluminum-ion batteries[J]. Chinese Journal of Applied Chemistry, 2023, 40(10): 1347-1358. (in Chinese). [5] 程军杰, 曹智, 杨灿然, 等. 便携式远程激光诱导击穿光谱系统及其定量分析性能[J]. 应用化学,2022,39(9):1447-1452.CHENG J J, CAO ZH, YANG C R, et al. Quantitative analysis with a portable remote laser-induced breakdown spectroscopy system[J]. Chinese Journal of Applied Chemistry, 2022, 39(9): 1447-1452. (in Chinese). [6] MA L H, WANG W, ZHOU CH, et al. A laser absorption sensor for fuel slip monitoring in high-humidity flue gases from ammonia combustion[J]. Measurement Science and Technology, 2023, 34(9): 094005. doi: 10.1088/1361-6501/acd94b [7] ZHANG H J, WU T, WU Q, et al. Methane detection with a near-infrared heterodyne phase-sensitive dispersion spectrometer at a stronger frequency modulation using direct injection-current dithering[J]. Optics Express, 2023, 31(15): 25070-25081. doi: 10.1364/OE.495581 [8] LI Q, JI F Y, WANG W, et al. A mid-infrared laser absorption sensor for calibration-free measurement of nitric oxide in laminar premixed methane/ammonia cofired flames[J]. Microwave and Optical Technology Letters, 2024, 66(1): e33815. doi: 10.1002/mop.33815 [9] PELÉ R, BREQUIGNY P, BELLETTRE J, et al. Performances and pollutant emissions of spark ignition engine using direct injection for blends of ethanol/ammonia and pure ammonia[J]. International Journal of Engine Research, 2024, 25(2): 320-333. doi: 10.1177/14680874231170661 [10] 杨舒涵, 乔顺达, 林殿阳, 等. 基于可调谐半导体激光吸收光谱的氧气浓度高灵敏度检测研究[J]. 中国光学,2023,16(1):151-157. doi: 10.37188/CO.2022-0029YANG SH H, QIAO SH D, LIN D Y, et al. Research on highly sensitive detection of oxygen concentrations based on tunable diode laser absorption spectroscopy[J]. Chinese Optics, 2023, 16(1): 151-157. (in Chinese). doi: 10.37188/CO.2022-0029 [11] 杨天悦, 宫廷, 郭古青, 等. 氨气高精度激光光谱检测装置的设计及实现[J]. 中国光学,2023,16(5):1129-1136. doi: 10.37188/CO.2023-0023YANG T Y, GONG T, GUO G Q, et al. Design and achievement of a device for high-precision ammonia gas detection based on laser spectroscopy[J]. Chinese Optics, 2023, 16(5): 1129-1136. (in Chinese). doi: 10.37188/CO.2023-0023 [12] 黄慧, 周亦辰, 彭宇, 等. 基于量子级联激光器中红外光谱技术的幽门螺旋杆菌呼气诊断的可行性研究[J]. 分析化学,2022,50(9):1328-1335.HUANG H, ZHOU Y CH, PENG Y, et al. Feasibility study of breath diagnosis in Helicobacter pylori based on quantum cascade laser mid-infrared spectroscopy[J]. Chinese Journal of Analytical Chemistry, 2022, 50(9): 1328-1335. (in Chinese). [13] 胡晓, 倪世传, 杨娜娜, 等. 用于氢过氧自由基光谱和动力学分析的腔衰荡光谱装置[J]. 分析化学,2023,51(6):994-1002.HU X, NI SH CH, YANG N N, et al. A cavity ring-down spectrum instrument for analysis of HO2 radical spectroscopy and kinetics[J]. Chinese Journal of Analytical Chemistry, 2023, 51(6): 994-1002. (in Chinese). [14] 聂伟, 阚瑞峰, 杨晨光, 等. 可调谐二极管激光吸收光谱技术的应用研究进展[J]. 中国激光,2018,45(9):911001. doi: 10.3788/CJL201845.0911001NIE W, KAN R F, YANG CH G, et al. Research progress on the application of tunable diode laser absorption spectroscopy[J]. Chinese Journal of Lasers, 2018, 45(9): 911001. (in Chinese). doi: 10.3788/CJL201845.0911001 [15] 朱晓睿, 卢伟业, 饶雨舟, 等. TDLAS直接吸收法测量CO2的基线选择方法[J]. 中国光学,2017,10(4):455-461. doi: 10.3788/co.20171004.0455ZHU X R, LU W Y, RAO Y ZH, et al. Selection of baseline method in TDLAS direct absorption CO2 measurement[J]. Chinese Optics, 2017, 10(4): 455-461. (in Chinese). doi: 10.3788/co.20171004.0455 [16] 房超, 乔顺达, 何应, 等. T字头石英音叉的设计及其气体传感性能[J]. 光学学报,2023,43(18):1899910. doi: 10.3788/AOS231163FANG CH, QIAO SH D, HE Y, et al. Design and sensing performance of t-shaped quartz tuning forks[J]. Acta Optica Sinica, 2023, 43(18): 1899910. doi: 10.3788/AOS231163 [17] MA Y F, HE Y, TONG Y, et al. Quartz-tuning-fork enhanced photothermal spectroscopy for ultra-high sensitive trace gas detection[J]. Optics Express, 2018, 26(24): 32103-32110. doi: 10.1364/OE.26.032103 [18] 聂伟, 许振宇, 阚瑞峰, 等. 可调谐二极管激光吸收光谱技术测量低温流场水汽露点温度[J]. 光学 精密工程,2018,26(8):1862-1869. doi: 10.3788/OPE.20182608.1862NIE W, XU ZH Y, KAN R F, et al. Measurement of low water vapor dew-point temperature based on tunable diode laser absorption spectroscopy[J]. Optics and Precision Engineering, 2018, 26(8): 1862-1869. (in Chinese). doi: 10.3788/OPE.20182608.1862 [19] 臧益鹏, 许振宇, 夏晖晖, 等. 基于免标定波长调制技术的高温谱线参数测量方法[J]. 中国激光,2020,47(10):1011001. doi: 10.3788/CJL202047.1011001ZANG Y P, XU ZH Y, XIA H H, et al. Method for measuring high temperature spectral line parameters based on calibration-free wavelength modulation technology[J]. Chinese Journal of Lasers, 2020, 47(10): 1011001. (in Chinese). doi: 10.3788/CJL202047.1011001 [20] RIEKER G B, JEFFRIES J B, HANSON R K. Calibration-free wavelength-modulation spectroscopy for measurements of gas temperature and concentration in harsh environments[J]. Applied Optics, 2009, 48(29): 5546-5560. doi: 10.1364/AO.48.005546 [21] WYSOCKI G, WEIDMANN D. Molecular dispersion spectroscopy for chemical sensing using chirped mid-infrared quantum cascade laser[J]. Optics Express, 2010, 18(25): 26123-26140. doi: 10.1364/OE.18.026123 [22] MARTÍN-MATEOS P, ACEDO P. Heterodyne phase-sensitive detection for calibration-free molecular dispersion spectroscopy[J]. Optics Express, 2014, 22(12): 15143-15153. doi: 10.1364/OE.22.015143 [23] MARTíN-MATEOS P, HAYDEN J, ACEDO P, et al. Heterodyne phase-sensitive dispersion spectroscopy in the mid-infrared with a quantum cascade laser[J]. Analytical Chemistry, 2017, 89(11): 5916-5922. doi: 10.1021/acs.analchem.7b00303 [24] PAUL S, MARTÍN-MATEOS P, HEERMEIER N, et al. Multispecies heterodyne phase sensitive dispersion spectroscopy over 80 nm using a MEMS-VCSEL[J]. ACS Photonics, 2017, 4(11): 2664-2668. doi: 10.1021/acsphotonics.7b00704 [25] DING W W, SUN L Q, YI L Y, et al. Dual-sideband heterodyne of dispersion spectroscopy based on phase-sensitive detection[J]. Applied Optics, 2016, 55(31): 8698-8704. doi: 10.1364/AO.55.008698 [26] 丁武文, 孙利群. 相敏式激光啁啾色散光谱技术在高吸收度情况下的应用[J]. 物理学报,2017,66(12):120601. doi: 10.7498/aps.66.120601DING W W, SUN L Q. Phase sensitive chirped laser dispersion spectroscopy under high absorbance conditions[J]. Acta Physica Sinica, 2017, 66(12): 120601. (in Chinese). doi: 10.7498/aps.66.120601 [27] MA L H, WANG ZH, CHEONG K P, et al. Mid-infrared heterodyne phase-sensitive dispersion spectroscopy in flame measurements[J]. Proceedings of the Combustion Institute, 2019, 37(2): 1329-1336. doi: 10.1016/j.proci.2018.06.184 [28] MA L H, WANG ZH, CHEONG K P, et al. Temperature and H2O sensing in laminar premixed flames using mid-infrared heterodyne phase-sensitive dispersion spectroscopy[J]. Applied Physics B, 2018, 124(6): 117. doi: 10.1007/s00340-018-6990-1 [29] DUAN K, HU M Y, JI Y B, et al. High-temperature ammonia detection using heterodyne phase-sensitive dispersion spectroscopy at 9.06 μm[J]. Fuel, 2022, 325: 124852. doi: 10.1016/j.fuel.2022.124852 [30] HU M Y, REN W. Wavelength-modulation dispersion spectroscopy of NO with heterodyne phase-sensitive detection[J]. Optics Letters, 2022, 47(11): 2899-2902. doi: 10.1364/OL.460042 [31] LOU X T, WANG Y, DONG Y K. Multipoint dispersion spectroscopic gas sensing by optical FMCW interferometry[J]. Optics Letters, 2021, 46(23): 5950-5953. doi: 10.1364/OL.443126 [32] TOLL J S. Causality and the dispersion relation: logical foundations[J]. Physical Review, 1956, 104(6): 1760-1770. doi: 10.1103/PhysRev.104.1760 -
下载:
点击查看大图
计量
- 文章访问数: 105
- HTML全文浏览量: 53
- PDF下载量: 18
- 被引次数: 0
