中国光学（中英文）2024，Vol.17Issue(4)：789-800,12.DOI:10.37188/CO.2023-0177
基于外差相敏色散光谱技术的宽动态范围甲烷气体检测
Measurement of methane concentration with wide dynamic range using heterodyne phase-sensitive dispersion spectroscopy
摘要
Abstract
In this paper,we developed a dual-sideband beat-suppressed heterodyne phase-sensitive disper-sion spectroscopy(HPSDS)for sensitive detection of trace gases across a wide dynamic range and explored the operational characteristics of the electro-optic modulator(EOM)and bias voltage control methods under sideband suppression mode.The dispersion phase spectral profiles and the corresponding signal-to-noise ra-tios in both suppression and non-suppression modes were compared before a comprehensive evaluation of the detection performance.A HPSDS-based detection system was developed based on a near-infrared distributed feedback laser and an EOM.The suppression of the dual-sideband beat was achieved by exploring and ana-lyzing 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-fre-quency(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 concentra-tions was then summarized.Meanwhile,wavelength modulation spectroscopy(WMS)experiments were con-ducted;subsequently,the HPSDS and WMS techniques'performances were compared in terms of linearity,dynamic detection range,and immunity to optical power fluctuations.Finally,the HPSDS-based system's performance under a wide dynamic range and rapid time response was verified by measuring different con-centrations of standard gases.Experimental results indicate that the HPSDS technique exhibits high linearity(R2=0.9999),a wide dynamic range(38.5 ppm to 40% ),and remarkable immunity to optical power fluctu-ations.The dual-sideband-beat-suppression-HPSDS-based methane sensor developed in this paper shows great potential for applications involving wide dynamic range detection and on-site practical trace gas detec-tion.关键词
相敏检测/色散光谱/双边带拍频抑制/甲烷检测/宽动态范围Key words
phase-sensitive detection/dispersion spectroscopy/dual-sideband beat suppression/methane de-tection/wide dynamic range分类
数理科学引用本文复制引用
周晨,马柳昊,王宇..基于外差相敏色散光谱技术的宽动态范围甲烷气体检测[J].中国光学（中英文）,2024,17(4):789-800,12.基金项目
国家自然科学基金项目(No.52106221) （No.52106221）
中国科学院长春光学精密机械与物理研究所应用光学国家重点实验室开放基金项目(No.SKLA02022001A05)Supported by National Natural Science Foundation of China(No.52106221) （No.SKLA02022001A05）
Open fund of State Key Laborat-ory of Applied Optics,CAS(No.SKLA02022001A05) （No.SKLA02022001A05）
