基于光纤光栅与花生型光纤级联结构的传感器特性及其应用研究

发布时间：2019-05-20 16:20

【摘要】：光纤传感器具有抗电磁干扰、灵敏度高、小巧、耐腐蚀等优点,因而在传感领域具有广泛的应用。本文提出了基于光纤光栅与花生型光纤级联结构和基于倾斜光纤光栅与花生型光纤级联结构的两种光纤传感器,对其弯曲传感特性和温度传感特性进行了详细研究。主要研究内容为:1、提出了一种基于光纤光栅与花生型光纤级联结构的全光纤传感器。利用耦合模理论对该传感器的弯曲传感特性进行了理论分析,花生型结构的引入可以有效增强光纤光栅中纤芯模与包层模间的耦合。基于光束传播法,选用仿真软件Rsoft对花生型光纤结构的光传输特性进行了模拟分析。结果表明,花生型结构能够有效激发出包层模式,随着花生型结构双球直径的增加,基模功率逐渐降低。2、通过优化控制光纤熔接机程序参数,制作了花生型光纤结构。将其与光纤光栅级联熔接,构成一种基于光纤光栅与花生型光纤级联结构的传感器。搭建了基于该传感器的全光纤传感装置,并对其弯曲、温度传感特性进行了详细的研究。实验结果表明,随着光纤弯曲曲率增加,探测器接收到的包层模功率逐渐减小,而纤芯模功率则几乎不变。当光纤弯曲曲率由0增加2.2m-1,探测器接收到的包层模功率减小4.64dB。随着环境温度的增加,系统测量的反射光谱红移。当环境温度从20℃逐渐升高到80℃时,反射光谱峰值波长向长波方向移动了0.6nm。而包层模、纤芯模功率未发生明显的改变。3、提出并制作了一种基于倾斜光纤光栅与花生型光纤级联结构的光纤传感器,搭建了基于该传感器的全光纤传感装置,并对其弯曲传感特性进行了研究。研究发现,倾斜光纤光栅的采用大大增加了传感器的反射包层模功率量级。与基于FBG与花生型光纤级联结构的传感器相比,反射功率包层模功率增加了38dB。而且包层模功率随弯曲曲率的增加,逐渐减小。当曲率由0 m-1增加1.77m-1时,包层模功率改变了2dB。
[Abstract]:Optical fiber sensor has many advantages, such as anti-electromagnetic interference, high sensitivity, small size, corrosion resistance and so on, so it has a wide range of applications in the field of sensing. In this paper, two kinds of fiber sensors based on fiber grating and flower type fiber cascade structure and inclined fiber grating and flower type fiber cascade structure are proposed, and their bending sensing characteristics and temperature sensing characteristics are studied in detail. The main research contents are as follows: 1. An all-fiber sensor based on fiber grating and flower type fiber cascade structure is proposed. The bending sensing characteristics of the sensor are analyzed theoretically by using the coupling mode theory. The introduction of floral structure can effectively enhance the coupling between core mode and wrapped mode in fiber gratings. Based on the beam propagation method, the optical propagation characteristics of floral fiber structure are simulated and analyzed by using the simulation software Rsoft. The results show that the flower type structure can effectively excite the coating mode. With the increase of the diameter of the double sphere of the flower type structure, the fundamental mode power decreases gradually. 2. By optimizing the program parameters of the optical fiber welding machine, the flower type optical fiber structure is fabricated. A sensor based on fiber grating and flower type fiber cascade structure is constructed by concatenating it with fiber grating. An all-fiber sensing device based on the sensor is built, and its bending and temperature sensing characteristics are studied in detail. The experimental results show that with the increase of the bending curvature of the optical fiber, the power of the coating mode received by the detector decreases gradually, while the power of the core mode is almost unchanged. When the bending curvature of the optical fiber increases from 0 to 2.2 m 鈮，

本文编号：2481775