摘要
为实现痕量气体的高灵敏度检测,本文提出了一种基于反谐振空芯光纤的全光纤气体检测系统,采用光纤环形腔衰荡光谱技术对一氧化碳(CO)气体进行测量。通过VPI光学仿真软件和有限元方法搭建该系统的仿真模型,对不同体积浓度梯度的CO气体开展仿真实验。结果表明:通过引入掺铒光纤放大器补偿腔内损耗并进行增益调谐,系统灵敏度较未放大系统提高约16.7倍。针对0%~0.02%体积分数梯度的CO气体,最大平均相对误差为0.4%。该系统的灵敏度为0.795 s,稳定性为0.82%,对CO气体体积分数的最低检测限为3.0757×10^(-11)。此研究对于痕量气体检测的性能优化具有理论指导意义。
Objective Residential gas leaks,vehicle exhaust,and industrial emissions all contain carbon monoxide(CO),a colorless,odorless,and extremely poisonous gas produced by the incomplete combustion of fuels containing carbon.Public safety,industrial production,and environmental quality are all seriously threatened by CO,which can cause acute poisoning or even death in humans at very low amounts.Therefore,it is crucial to create ultra-sensitive CO detection technology to protect human health,industrial operations,and environmental monitoring.Researchers have recently focused a lot of attention on anti-resonant hollow-core fiber(AR-HCF)because of its special benefits,which include low transmission loss,large core diameter,small optical stripe amplitude,compact structure,and the ability to enable long-distance continuous interaction between single-mode radiation and the target gas.These features give AR-HCF a lot of potential for use in gas sensing applications.In order to achieve high sensitivity,high stability,and compact trace CO detection,this study proposes an all-fiber gas detection system based on AR-HCF for CO monitoring employing fiber loop ring down spectroscopy.Methods In this work,an all-fiber CO detection system based on fiber ring cavity decay spectroscopy was built,using a continuous wave(CW)laser with a central wavelength of 1567 nm as the light source and AR-HCF as the gas chamber sensing element.The AR-HCF'transmission characteristics were first examined using the finite element approach,with an emphasis on its limiting loss at the operating wavelength of 1567 nm.The ideal length of the AR-HCF gas chamber was then determined by methodically examining the link between the sensitivity of the hollow-core gas chamber and the optical path length.Erbium-doped fiber amplifier(EDFA)with varying gain values were incorporated into the fiber ring cavity to boost the effective number of laser cycles and offset the intrinsic cavity loss in order to further improve the detection sensitivity.In order to thoroughly assess the detection performance of the developed system,a number of performance tests were carried out,including stability testing through repeated measurements and concentration detection tests in the range of 0-0.02%.Results and Discussions The research using the finite element approach showed that the AR-HCF'limiting loss at 1567 nm was roughly 0.92 dB/km.A 1-meter-long AR-HCF was chosen as the gas chamber structure after research into the relationship between optical path length and sensitivity revealed that the detection sensitivity increased with the length of the optical path.This was done while taking system compactness and practical applicability into full consideration.The findings of the experiment showed that increasing the EDFA gain greatly increased the system's sensitivity:the system's sensitivity with a 2 dB gain ring cavity was 16.7 times greater than that of the system without EDFA.With a correlation value(R²)of 0.99989,concentration detection experiments verified a strong linear relationship between the decay time and CO concentration in the range of 0%-0.02%.The greatest average relative error was only 0.4%,according to stability tests with ten repeated measurements for various CO concentration gradients.In the end,the developed system demonstrated outstanding detection performance and reliability with a minimum detection limit of 3.0757×10^(-11),a sensitivity of 0.795 s,and a stability of 0.82%.Conclusions This work effectively creates an all-fiber CO detection system using fiber loop ring down spectroscopy in conjunction with AR-HCF.The system achieves ultra-high sensitivity and stability in trace CO detection by utilizing the superior performance of AR-HCF and the gain compensating effect of EDFA.The system offers a new and efficient technical method for trace gas detection thanks to its benefits of strong anti-interference ability,compact structure,high detection sensitivity,and dependable performance.It not only improves the technical methods of CO detection but also has great potential for use in areas including public health protection,environmental quality monitoring,and industrial safety early warning.In order to increase the detection limit and broaden the system's application scope to more trace gas detection scenarios,future research can concentrate on improving the fiber cavity construction and EDFA gain control.
作者
鲁恬
吕子啸
李旺旺
孟腾飞
丁相午
闫兴钰
韩丙辰
Lu Tian;Lv Zixiao;Li Wangwang;Meng Tengfei;Ding Xiangwu;Yan Xingyu;Han Bingchen(Department of Physics,Taiyuan Normal University,Jinzhong,Shanxi 030600,China;Sinogreen Environmental Technology Co.,Ltd.,Taiyuan,Shanxi 030032,China;Shanxi Key Laboratory for Intelligent Optimization Computing and Blockchai Technology,Jinzhong,Shanxi 030600,China)
出处
《光电工程》
北大核心
2026年第2期77-86,共10页
Opto-Electronic Engineering
基金
国家自然科学基金资助项目(62441110)
山西省基础研究计划青年项目(202203021212191)
太原市“双百攻关行动”“揭榜挂帅”项目(38)。
关键词
光谱学
反谐振空芯光纤
光纤环形腔衰荡光谱技术
气体检测
灵敏度
spectroscopy
anti-resonant hollow-core fiber
fiber loop ring-down spectroscopy
gas detection
sensitivity
