保偏光子晶体光纤模间干涉弯曲传感特性研究

发布时间：2018-01-05 18:43

本文关键词：保偏光子晶体光纤模间干涉弯曲传感特性研究　出处：《燕山大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着科学技术的发展,光纤弯曲传感器基于光纤的电绝缘、质量轻、柔韧性好、体积小、抗电磁干扰等特点应用于航天航空、地球物理、建筑物健康监测等领域中。光纤弯曲传感器是强度调制型光纤传感器,传统的光纤弯曲传感器是通过弯曲光纤导致光纤传输光强的损耗变化间接测量温度、压力、流量、速度、应变等环境参量。然而,由于传统的光纤弯曲传感器损耗因素多难以精确计算环境参量的变化,而且大多使用光谱仪探测价格昂贵。因此,研究一种原理较成熟、误差因素少以及方便测试的新型光纤弯曲传感器具有重要意义。在现有的保偏光子晶体光纤模间干涉传输特性研究的基础上,本课题利用保偏光子晶体光纤模间干涉原理设计了一种新型的光纤弯曲传感器,在理论分析和仿真的基础上,对所设计的光纤弯曲传感器进行了实验研究。论文的主要内容有:首先,利用电磁场理论分析保偏光纤模式特性,并由此引出保偏光子晶体光纤模间干涉理论,研究了低阶模LP01模和LP11模之间的干涉特性。其次,采用有限元分析法,对保偏光子晶体光纤双模工作波长范围、模场面积以及模间干涉灵敏度等进行分析研究,并对类矩形光子晶体光纤、椭圆芯保偏光纤以及双空气孔光子晶体光纤的模间干涉特性进行比较分析,最终确定了双空气孔光子晶体光纤作为光纤弯曲传感器的传感光纤。然后,利用有限差分光束传输法,模拟计算双空气孔光子晶体光纤模场分布,即LP01模和LP11模的有效折射率和电场分布的变化。进而研究了在不同弯曲方向以及不同弯曲半径下的模场分布的变化。并仿真计算模间干涉结果,给出了干涉光强分布与弯曲半径之间的关系,讨论了波长对弯曲传感灵敏度的影响。最后,通过设计搭建实验平台,对双空气孔光子晶体光纤模间干涉特性进行了实验验证。设计并实现了弯曲测试系统,进行了弯曲传感器特性的实验研究,并对实验误差进行了分析,为将来进一步研究提供优化方向。
[Abstract]:With the development of science and technology, optical fiber bending sensor based on electrical insulation, light weight, good flexibility, small volume, anti electromagnetic interference and other characteristics used in aerospace, geophysical field, the structural health monitoring. Optical fiber bending sensor is intensity modulated optical fiber sensor, the traditional optical fiber bending sensor is caused by bending fiber temperature measurement, indirect loss changes in optical fiber transmission intensity of pressure, flow, velocity, strain and other environmental parameters. However, due to changes in optical fiber bending sensor loss factor of traditional and more difficult to accurately calculate the environmental parameters, and most of the use of spectrometer is expensive. Therefore, study on the principle of a mature, less error factors is of great significance and convenient test model optical fiber bending sensor. Based on the transmission characteristics of interference in the existing polarization maintaining photonic crystal fiber mode on, The subject of the use of polarization maintaining photonic crystal fiber intermodeinterference principle to design a new type of optical fiber bending sensor, on the basis of theory analysis and simulation, the design of optical fiber bending sensor was studied. The main contents of this paper are: firstly, analysis thepmf mode based on the characteristics of the theory of electromagnetic field, and thus leads to polarization maintaining photonic crystal fiber mode interference theory, studied the interference characteristics between the low order mode LP01 mode and LP11 mode. Secondly, using the method of finite element analysis of polarization maintaining photonic crystal fiber dual wavelength range, analyze the scene and intermodeinterference die product sensitivity, and the class of rectangular photonic crystal fiber partial, optical fiber and die hole photonic crystal fiber with dual air interference characteristics were compared and ultimately determine the elliptical core, two hole photonic crystal fiber as the optical fiber bending sensor The sensing optical fiber. Then, by using the finite difference beam propagation method, the simulation calculation of double hole photonic crystal fiber mode field distribution of LP01 mode and LP11 mode effective refractive index and the changes of the electric field distribution. And then studied in different bending direction and bending radius under the different distribution of the modes and simulation changes. Modular interference results, the relationship between the distribution of interference intensity and the bending radius is given, the effect of wavelength on the bending sensitivity is discussed. Finally, through the design of the experimental platform is built, on photonic crystal fiber mode dual air hole interference characteristics in the experiment. The design and implementation of bending test system, experimental study on bending sensor performance has been carried out, and the experimental error was analyzed for further study in the future to provide the optimization direction.

【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN253

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