长距离光纤折射率传感技术研究

发布时间：2018-01-06 16:41

本文关键词：长距离光纤折射率传感技术研究　出处：《中国计量学院》2015年硕士论文　论文类型：学位论文

【摘要】：长距离的实时监测在一些应用领域中具有非常重要的作用,比如化工产业,海洋环境评估和管道安全监测等领域。折射率参数作为物质的内在属性,与物质的化学、物理性质之间有着非常密切的联系。所以在一些的应用领域中,对折射率进行长距离的实时性检测具有非常重要的实际意义。本论文主要研究内容为长距离的折射率传感技术,具体研究内容如下:1、基于光时域反射技术提出了一种反射型的长距离折射率传感器。该传感器通过测量光纤端面与样品溶液之间的菲涅尔反射信号,能够轻易地获得一定距离以外的折射率变化信息。该传感器具有制作简单、操作方便等优点。实验结果表明了该传感器能够实现的测量距离可达100.8km,在折射率范围1.3486~1.4525,折射率的灵敏度范围为38.71 d B/RIU~304.89 d B/RIU。实验还通过人为的施加干扰验证了该传感器具有较好的稳定性和准确性,在长距离的折射率传感领域中具有较好的应用前景。2、提出并实现了一种基于菲涅尔反射的准分布折射率传感器。利用光耦合器从光纤链路上分出的光纤末梢切平后被作为折射率传感头。在多个折射率传感头之间采用不同长度的延迟光纤,利用不同位置传感处的菲涅尔反射信号回到测量端的时间差来实现距离可分辨的多点测量。我们通过实验实现了测量距离为16公里双点折射率传感,并表明了该传感器在折射率范围1.3486~1.4525,其对应的灵敏度范围为38.785d B/RIU~305.430d B/RIU。实验还通过增加传感头的数量进一步验证了该传感器的多点复用能力。3、提出了一种基于反射型长周期光纤光栅(Long Period Fiber Grating,LPFG)的长距离双参数传感技术,该传感技术通过连接LPFG和Sagnac干涉环实现了折射率与温度的同时监测。在一个传统的LPFG末端连接一个Sagnac干涉环,是LPFG工作在反射模式,这种结构更适合一些长距离传感。因为LPFG与Sagnac具有不同的温度和折射率灵敏度,所以可以通过监测LPFG的谐振峰和Sagnac干涉峰的波长移动来同时获得温度和折射率值。实验结果表明,该传感器的温度灵敏度为1.533nm/°C,在折射率范围1.333~1.430,折射率灵敏度为16.864nm/RIU~113.142nm/RIU。实验利用该传感器实现了的40km折射率和温度的同时传感,证明了该传感器在长距离的双参数传感领域中具有良好的应用前景。
[Abstract]:Long-distance real-time monitoring plays an important role in some applications, such as chemical industry, marine environmental assessment and pipeline safety monitoring. Refractive index parameters are the intrinsic properties of materials. There is a very close relationship with the chemical and physical properties of substances. So in some fields of application. It is very important to detect the refractive index in real time with long distance. The main content of this thesis is the refractive index sensing technology of long distance. The specific research contents are as follows: 1. Based on the optical time domain reflectance technique, a reflective long distance refractive index sensor is proposed, which measures the Fresnel reflection signal between the optical fiber end surface and the sample solution. The information of refractive index change beyond a certain distance can be easily obtained.; the sensor has simple fabrication. The experimental results show that the measuring distance of the sensor can reach 100.8km, and the refractive index is 1.3486n 1.4525. The sensitivity range of refractive index is 38.71 dB / RIUN 304.89 d. B / RIU. experiments also verify the stability and accuracy of the sensor by artificial interference. It has a good application prospect in the field of long-range refractive index sensing. A quasi-distributed refractive index sensor based on Fresnel reflectance is proposed and realized. The optical fiber tip which is separated from the fiber link by optical coupler is used as the refractive index sensor head. With different lengths of delay fiber. Using the time difference of Fresnel reflection signal at different positions to get back to the measuring end to realize the range resolution multipoint measurement, we have realized the measurement distance of 16 km double point refractive index sensor. It is shown that the sensor is in the refractive index range of 1.3486U 1.4525. The corresponding sensitivity range is 38.785d, B / R, 305.430d. By increasing the number of sensor heads, the experiment further verifies the multipoint multiplexing capability of the sensor. 3. A long distance two-parameter sensing technique based on long Period Fiber grating (LPFG) is proposed. The sensing technique realizes the simultaneous monitoring of refractive index and temperature by connecting the LPFG and Sagnac interference rings. A Sagnac interference ring is connected at the end of a traditional LPFG. LPFG works in reflection mode, and this structure is more suitable for some long-range sensing because LPFG and Sagnac have different temperature and refractive index sensitivity. Therefore, the temperature and refractive index can be obtained simultaneously by monitoring the wavelength shift of the resonant peak of LPFG and the wavelength shift of the interference peak of Sagnac. The temperature sensitivity of the sensor is 1.533 nm / 掳C, and the refractive index is 1.333 nm / 掳C. The refractive index sensitivity is 16.864 nm / r IUN 113.142nm / r RIU. The 40 km refractive index and temperature sensor is used in the experiment. It is proved that the sensor has a good application prospect in the field of long distance two-parameter sensor.
【学位授予单位】：中国计量学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN253

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