基于拉锥七芯光纤的湿度传感器研究  

Research on Humidity Sensor Based on Tapered Seven Core Fiber

作　　者：徐妍妍[1,2] 李俊 李浩[1,2] 赵雨佳[1] 徐明靖 刘佳欣 蒋佩蓁 周爱 Xu Yanyan;Li Jun;Li Hao;Zhao Yujia;Xu Mingjing;Liu Jiaxin;Jiang Peizhen;Zhou Ai(National Engineering Laboratory for Fiber Optical Sensing Technology,Wuhan University of Technology,Wuhan,Hubei 430074,China;School of Materials Science and Engineering,Wuhan University of Technology,Wuhan,Hubei 430074,China)

机构地区：[1]武汉理工大学光纤传感技术国家工程实验室,湖北武汉430074 [2]武汉理工大学材料科学与工程学院,湖北武汉430074

出　　处：《中国激光》2021年第23期93-102,共10页Chinese Journal of Lasers

摘　　要：提出了一种基于拉锥七芯光纤的湿度传感器,七芯光纤熔接于两段单模光纤(SMF)的中间,利用氢氧焰拉锥技术对七芯光纤进行熔融拉锥,光纤拉锥后因其激发的包层基模和高阶模之间发生干涉形成马赫-曾德尔干涉仪(MZI)。研究结果表明光纤直径越小,传感结构的折射率灵敏度越高,锥区直径为10μm时传感结构的灵敏度最高为1123 nm/RIU。将七芯光纤与亲水性材料氧化石墨烯(GO)薄膜结合制得湿度传感器,实验测得湿度灵敏度的最大值为-0.0535 nm/(%RH)。该传感器具有灵敏度高、制备简单、稳定性好的优势,可广泛应用于生物化学传感领域。Objective The monitoring of relative humidity is very important in the fields of agriculture,medical treatment and biochemical research,which urges scholars to develop various humidity sensors.Among many humidity sensors,optical fiber humidity sensor has become a research hotspot owing to their unique advantages such as high sensitivity,anti-electromagnetic interference,compact structure and other unique advantages.There are many kinds of optical fiber humidity sensors,and the interferometric humidity sensor has attracted wide attention because of its advantages of simple preparation and high sensitivity,among which the humidity sensor based on Mach-Zehnder interferometer(MZI)is widely used.However,the sensitivity and stability of these sensors still need to be further improved.In order to improve the sensitivity of the sensor and maintain its stability,a humidity sensor based on seven core tapered fiber is proposed and demonstrated.The sensor consists of a short section of seven core fiber between two single-mode fibers,in which the seven core fiber is fused and tapered by a hydrogen oxygen flame to form a tapered structure.Mach-Zehnder interferometer is formed by interference between the base mode of the cladding and the higher mode excited after the fiber is tapered.The effective refractive index of the cladding mode is easily affected by the external environment parameters.Therefore,the structure is very sensitive to the changes of the external environment parameters.The proposed structure is particularly suitable for the situations where high measurement sensitivity and high stability are required.Methods Firstly,the seven core fiber with a length of about 1 cm is fused between two single-mode fibers.Then,the seven core fiber in the sensing structure is fused and tapered by a fiber taper machine(Kaipule Co.Ltd.AFBT-8000 MX-H).Finally,GO film is coated on the surface of the tapered area by photothermal method.The coating process is as follows:the GO prepared by the improved Hummers method is mixed into a solu

关 键 词：光纤光学 光纤传感 熔融拉锥 湿度 氧化石墨烯 

分 类 号：TN25[电子电信—物理电子学]