基于磁旋转光谱技术的氧气传感器  

Oxygen Sensor Based on Faraday Rotation Spectroscopy

作　　者：刘栋沅 方波[1] 赵卫雄[1] 胡晓 张为俊[1,2,3] Liu Dongyuan;Fang Bo;Zhao Weixiong;Hu Xiao;Zhang Weijun(Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,Anhui,China;University of Science and Technology of China,Hefei 230026,Anhui,China;School of Environmental Science and Optoelectronic Technology,University of Science and Technology of China,Hefei 230026,Anhui,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]中国科学技术大学环境科学与光电技术学院,安徽合肥230026

出　　处：《光学学报》2023年第24期368-375,共8页Acta Optica Sinica

基　　金：国家自然科学基金(U21A2028,42022051);第二次青藏高原综合科学考察研究(2019QZKK0606);中国科学院青年创新促进会(Y202089)。

摘　　要：在全球气候变化导致大气氧气浓度持续下降的背景下,为揭示青藏高原氧含量变化过程,利用氧气的顺磁性和法拉第磁光效应,研制了高精度磁旋转光谱大气氧气传感器。氧气测量选择近红外磁效应较强的13118.04 cm^(-1)波数处PP(1)(J=1)跃迁谱线,结合Herriott光学多通池将有效吸收光程提高至7 m,使用通电螺线管线圈提供180 Gs(1 Gs=10^(-4)T)直流磁场。基于噪声测量的信噪比分析显示装置中检偏器的最优偏转角为10°,此时系统总噪声为0.33μV/Hz^(1/2)。最优光谱参数条件下的Allan方差评估表明,系统的探测精度为32×10^(-6)(1σ,60 s)。本装置通过使用稀土永磁体代替通电螺线管线圈,有望进一步提高磁旋转光谱信号强度,提升传感器性能。Objective Oxygen(O_(2))is one of the most important components in the atmosphere and plays a key role in the survival of all living organisms on Earth.However,the atmospheric O_(2) concentration is decreasing due to the rapid expansion of human activities.The Tibet Plateau,known as the third pole,is a plateau with the highest altitude in the world.For a long time,as the O_(2) content of the local atmosphere is lower than that of other regions,the ecosystem is extremely fragile and sensitive.Long-term quantitative monitoring of atmospheric O_(2) concentration is crucial to understand the evolution pattern of decreasing O_(2) and its effects on the ecosystem of the Tibet Plateau.However,it requires a very challenging detection precision of 10^(-6) level.Various O_(2) measurement methods have been proposed.The commonly employed electrochemical techniques and magnetic dynamics methods are compact and easily commercial available but suffer from long-term stability and vibration.In contrast,laser absorption spectroscopic techniques based on the Beer-Lambert law can provide high reliability,completely non-contact measurement,and long-term performance.In particular,Faraday rotation spectroscopy further offers high selectivity for paramagnetic molecules and is a powerful tool for O_(2) measurement with high precision. Our paper develops a simply easy-to-deploy and maintenance-free O_(2) sensor based on FRS and provides a feasible sensor scheme for O_(2) detection in Tibetan Plateau.Methods A 762. 3 nm continuous wave distributed-feedback laser working at room temperature is employed as the probe laser. The laser current and temperature are controlled by a commercial laser controller. O_(2) measurement selects the PP(1)(J=1) line with a strong near-infrared magnetic effect and a strength of 3. 063×10^(-24) cm/molecule at 13118. 04 cm^(-1). The static magnetic field is generated by a solenoid coil under constant current excitation. A Herriott optical multi-pass cell with two 8 cm diameter spherical mirrors separated at 35

关 键 词：光谱学 磁旋转光谱技术 传感器 氧气 

分 类 号：O433.1[机械工程—光学工程]