Simultaneous detection of CH_(4)and CO_(2)through dual modulation off-axis integrated cavity output spectroscopy  

作　　者：刘艺璇 王周兵 韦欣欣 王静静 孟鑫 毛桂林 Yi-Xuan Liu;Zhou-Bing Wang;Xin-Xin Wei;Jing-Jing Wang;Xin Meng;Gui-Lin Mao(School of Physics and Electronic Engineering,Jiangsu Normal University,Xuzhou 221116,China)

机构地区：[1]School of Physics and Electronic Engineering,Jiangsu Normal University,Xuzhou 221116,China

出　　处：《Chinese Physics B》2023年第10期468-475,共8页中国物理B（英文版）

基　　金：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);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 2.67×10^(-13)cm^(-1)·Hz^(-1/2)and 5.18×10^(-11)cm^(-1)·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 

分 类 号：X831[环境科学与工程—环境工程] O433[机械工程—光学工程]