一次谐波锁频的快速光腔衰荡光谱检测  

Fast optical cavity ring-down spectroscopy detection based on first harmonic frequency locking

作　　者：胡迈 陈祥 张辉[3] 胡梦鹏 金文玲 李萌 阚瑞峰[1] HU Mai;CHEN Xiang;ZHANG Hui;HU Mengpeng;JIN Wenling;LI Meng;KAN Ruifeng(Anhui Institute of Optics and Fine Mechanics,Hefei Institute of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230026,China;Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;National Key Laboratory of Science and Technology on Tunable Laser,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]中国科学院合肥物质科学研究院安徽光学精密机械研究所,安徽合肥230031 [2]中国科学技术大学,安徽合肥230026 [3]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [4]哈尔滨工业大学可调谐激光技术国家级重点实验室,黑龙江哈尔滨150001

出　　处：《光学精密工程》2022年第4期363-371,共9页Optics and Precision Engineering

基　　金：国家重点研究发展计划项目(No.2019YFB2006003);国家自然科学基金项目(No.61805286);中国科学院环境光学与技术重点实验室开放基金项目(No.2005DP173065-2021-03);安徽省自然科学基金项目(No.2008085QF317)。

摘　　要：本文介绍了一种赫兹级响应速率的光腔衰荡光谱探测大气痕量气体的检测技术。将100 MHz正弦波调制信号加载在电光相位调制器上产生边带,用混频器提取载波与边带通过3 m气体吸收池后拍频所产生的一次谐波作为误差信号,实现了1572 nm分布式反馈激光器对于二氧化碳气体分子6361.25 cm^(-1)处超精细跃迁线的频率锁定。采用波分复用方法对空腔衰荡时间和有气体吸收时的衰荡时间进行同时测量,在330 mm光学谐振腔上得到了4.82×10^(-10) cm^(-1)的系统检测限。在较大的二氧化碳浓度范围内,系统具有良好的线性响应,线性相关系数大于0.9999。系统长时间的观测结果与Picarro商用仪器的数据高度吻合,二者偏差小于1.0%。该系统论证了一次谐波锁定激光频率至分子超精细跃迁线并用于光腔衰荡光谱系统实现快速痕量气体检测的可行性。Optical cavity ring-down spectroscopy with a Hz-level response rate is introduced to detect trace gases in the atmosphere.By loading a 100 MHz modulated sine wave signal on the electro-optic phase modulator that generates sidebands and using the mixer to extract the first harmonic generated as the error signal by the beat frequency of the carrier and sidebands after passing through the 3 m gas absorption cell,the frequency locking of a 1572 nm distributed feedback laser on the 6361.25 cm^(-1) hyperfine transition line of carbon dioxide gas molecule was achieved.The ring-down time of the cavity without gas and the ring-down time with gas absorption were simultaneously measured using the wavelength-division multi⁃plexing method,and the detection limit of the system obtained was 4.82×10^(-10) cm^(-1) on a 330 mm optical resonator.The system has a good linear response in a large carbon dioxide concentration range,and the linear correlation coefficient is greater than 0.999.The long-term observation results of the system are highly consistent with the data from Picarro commercial instruments,and the deviation between the two is less than 1.0%.The system proved the feasibility of locking the laser frequency to the molecular hyperfine transition line using the first harmonic and applying it to the optical cavity ring-down spectroscopy system to achieve a fast trace gas detection.

关 键 词：相位调制 一次谐波锁频 光腔衰荡光谱 快速痕量气体检测 

分 类 号：TP391[自动化与计算机技术—计算机应用技术] TH691.9[自动化与计算机技术—计算机科学与技术]