基于光纤光栅法珀干涉结构的热线式风速计  

Hot-wire Anemometer Based on Fiber Grating Fabry-Perot Interferometer

作　　者：林颖 唐玉涵 杜浪哲 徐鹏柏 董新永 LIN Ying;TANG Yuhan;DU Langzhe;XU Pengbai;DONG Xinyong(Institute of Advanced Photonics Technology,School of Information Engineering,Guangdong University of Technology,Guangzhou 510006,China;Key Laboratory of Photonic Technology for Integrated Sensing and Communication,Ministry of Education of China,Guangdong University of Technology,Guangzhou 510006,China;Guangdong Provincial Key Laboratory of Information Photonics Technology,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]广东工业大学信息工程学院先进光子技术研究院,广州510006 [2]广东工业大学通感融合光子技术教育部重点实验室,广州510006 [3]广东工业大学广东省信息光子技术重点实验室,广州510006

出　　处：《光子学报》2024年第12期146-154,共9页Acta Photonica Sinica

基　　金：国家自然科学基金(Nos.62361136584,11974083);广东省“珠江人才计划”引进创新创业团队项目(No.2019ZT08X340)。

摘　　要：为提高热线式光纤光栅风速计的性能,提出一种基于光纤光栅法珀干涉结构的热线式风速计。该风速计通过在两个光纤布拉格光栅的中间熔接一段长度为500μm的掺钴光纤以形成法珀干涉结构(FPI),该掺钴光纤吸收1480 nm激光后产生热量从而形成热线,根据热膨胀效应和热光效应,温度变化会引起掺钴光纤中光程的变化,使得FPI的干涉谱红移。当气流流过FPI风速计时,掺钴光纤的热量散失速率加快,温度降低进而导致FPI干涉谱蓝移,蓝移量与风速成固定的关系。因此,通过测量FPI干涉谱的波长改变量,可以计算出风速值。实验中,在0~9 m/s的范围进行了风速测量,获得热线式风速计的典型响应,灵敏度随风速增大逐渐降低。在风速为0.1 m/s时,风速计的灵敏度达到-1053.86 pm·m^(-1)·s,而风速为0.5 m/s和5.0 m/s时,灵敏度分别为-746.47 pm·m^(-1)·s和-15.15 pm·m^(-1)·s。与已报道的热线式光纤光栅风速计相比,所提出的光纤光栅FPI风速计具有灵敏度高、结构简单紧凑、易于制造、成本低等优点。Airflow velocity measurement is important in many fields such as meteorological monitoring and wind power generation.Currently,it is common to utilize ultrasonic,differential pressure,eddy current,or heat transfer methods for measuring.However,in some extreme environments,these measurements may be encounter interference,resulting in less accurate or non-functional results.Fiber optic anemometers have attracted much attention because of their advantages of electrically passive operation,resistance to electromagnetic interference,high sensitivity,integrated structure,and the ability to measure over long distances.In order to enhance the performance of fiber optic anemometers,this paper proposes a hot-wire anemometer based on fiber grating Fabry-Perot Interferometer(FPI)structure.Fiber grating FPI anemometers are prepared by sandwiching a section of cobalt-doped fiber with a length of 500μm in the middle of two Fiber Gratings(FBGs).The cobalt-doped fiber in the interference cavity is heated with a 1480 nm laser to form a hot wire.Due to the effect of thermal expansion and thermo-optic,the optical range difference of the FPI cavity length changes with the temperature of the cobalt-doped fiber,which brings about the wavelength redshift of the interference spectrum.As air flows through the FPI anemometer,the heat dissipation from the FPI is accelerated.The temperature of the FPI decreases,causing a blue shift in the interference spectrum,and the airflow velocity value can be calculated by measuring the change in the interference spectrum.We first performed temperature calibration experiments on the FPI anemometer probe by placing the anemometer probe in a temperature-controlled box.The output power of the broadband light source was set to 5 mW,and the output of the 1480 nm laser was turned off to avoid the heat generated by the cobalt-doped fiber absorbing the laser.The temperature of the temperature control box was adjusted to gradually increase from-20℃ to 110℃ in 10℃ steps,and the interference spectral drift

关 键 词：光纤传感器 热线式风速计 光纤布拉格光栅 法布里珀罗干涉仪 掺钴光纤 风速测量 

分 类 号：TP212.1[自动化与计算机技术—检测技术与自动化装置]