光纤中瑞利散射光的相位解调
发布时间：2018-08-02 16:49
【摘要】：由于光纤材料的不均匀性,光波在光纤中传输时将产生瑞利散射。利用瑞利散射光的分布式光纤传感技术已在周界安防、输油管道、高铁等结构安全健康监测领域发挥出重要作用。其中,基于相位解调的Φ-OTDR作为一种新型分布式声波传感系统,已成为目前光纤传感领域国内外的研究热点,其在石油勘探,地质结构分析等领域展现出不可忽视的优越性和巨大市场前景。然而,目前Φ-OTDR系统的相位解调方案在灵敏度、实时性和稳定性等方面都存在其固有缺陷。本文通过在Φ-OTDR系统中引入新的相位解调方式——基于90。光学混频器的相位解调,利用光纤中的瑞利散射光的相位解调实现分布式声波传感,克服了几种现有的相位解调方式存在的缺陷,对扩展Φ-OTDR应用、提升DAS性能具有重要意义。现将本文具体工作介绍如下：1.本文介绍了光纤中瑞利散射光以及基于瑞利散射光的分布式传感技术——Φ-OTDR的相关理论基础,包括：光纤中瑞利散射光相关原理；Φ-OTDR传感原理和几种现有的Φ-OTDR相位解调方案。2.本文提出基于90。光学混频器的瑞利散射光相位解调方式,并简述其解调原理和基于此解调方式的Φ-OTDR声波传感原理。3.本文进行了基于90。光学混频器搭建的外差检测的Φ-OTDR相位解调实验,实验证明基于此解调方案能够实现光纤中瑞利散射光的相位解调,且基于此方案的Φ-OTDR能够进行分布式声波传感。4. 本文搭建了基于零差检测的90。光学混频器的Φ-OTDR系统,并进行声波传感实验：分别利用自行编写的MATLAB程序和LABVIEW程序进行了离线和在线的分布式声波传感系统声波扰动实验；实验进一步证明基于90。光学混频器的相位解调方案的可行性,并对系统的频率响应平坦度和系统对不同声波振幅响应的线性度做了简要分析。5.本文对比了基于90°光学混频器的相位解调方案和现有的其他几种相位解调方案,得出基于90°光学混频器的相位解调的Φ-OTDR在声波传感方面具有系统稳定,实时性高,灵敏度高等优点的结论。
[Abstract]:Due to the inhomogeneity of fiber materials, Rayleigh scattering will occur when light waves propagate in optical fibers. The distributed optical fiber sensing technology using Rayleigh scattering light has played an important role in the field of perimeter security, oil pipeline, high iron and other structural safety and health monitoring. As a new distributed acoustic sensing system, 桅 -OTDR based on phase demodulation has become a hot spot in the field of optical fiber sensing. Geological structure analysis and other fields show great advantages and huge market prospects. However, the phase demodulation scheme of 桅 -OTDR system has its inherent defects in sensitivity, real-time and stability. This paper introduces a new phase demodulation method in 桅 -OTDR system based on 90. The phase demodulation of optical mixer, using Rayleigh scattering light in optical fiber to realize distributed acoustic sensing, overcomes the defects of several existing phase demodulation methods, and is of great significance to expand 桅 -OTDR application and improve the performance of DAS. The specific work of this article is introduced as follows: 1. This paper introduces the theoretical basis of Rayleigh scattering light in optical fiber and the distributed sensing technology-桅 -OTDR based on Rayleigh scattering light, including: correlation principle of Rayleigh scattering light in optical fiber, 桅 -OTDR sensing principle and several existing 桅 -OTDR phase demodulation schemes. In this paper, based on 90. The phase demodulation method of Rayleigh scattering light for optical mixers is presented. The demodulation principle and the principle of 桅 -OTDR acoustic wave sensing based on this demodulation method are briefly described. In this paper, based on 90. The 桅 -OTDR phase demodulation experiment of heterodyne detection built by optical mixer shows that this demodulation scheme can realize the phase demodulation of Rayleigh scattering light in optical fiber, and the 桅 -OTDR based on this scheme can carry out distributed acoustic wave sensing. 4. In this paper, a 90. 0 based on homodyne detection is built. The 桅 -OTDR system of optical mixer, and the acoustic wave sensing experiment: using the MATLAB program and LABVIEW program written by ourselves, the acoustic disturbance experiment of off-line and on-line distributed acoustic wave sensing system is carried out, which is further proved to be based on 90. The feasibility of the phase demodulation scheme of the optical mixer is discussed. The flatness of the frequency response of the system and the linearity of the response of the system to different acoustic amplitudes are analyzed briefly. In this paper, the phase demodulation scheme based on 90 掳optical mixer and several other phase demodulation schemes are compared. It is concluded that 桅 -OTDR based on 90 掳optical mixer is stable and real-time in acoustic sensing. A conclusion of high sensitivity.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN253
本文编号：2160066
[Abstract]:Due to the inhomogeneity of fiber materials, Rayleigh scattering will occur when light waves propagate in optical fibers. The distributed optical fiber sensing technology using Rayleigh scattering light has played an important role in the field of perimeter security, oil pipeline, high iron and other structural safety and health monitoring. As a new distributed acoustic sensing system, 桅 -OTDR based on phase demodulation has become a hot spot in the field of optical fiber sensing. Geological structure analysis and other fields show great advantages and huge market prospects. However, the phase demodulation scheme of 桅 -OTDR system has its inherent defects in sensitivity, real-time and stability. This paper introduces a new phase demodulation method in 桅 -OTDR system based on 90. The phase demodulation of optical mixer, using Rayleigh scattering light in optical fiber to realize distributed acoustic sensing, overcomes the defects of several existing phase demodulation methods, and is of great significance to expand 桅 -OTDR application and improve the performance of DAS. The specific work of this article is introduced as follows: 1. This paper introduces the theoretical basis of Rayleigh scattering light in optical fiber and the distributed sensing technology-桅 -OTDR based on Rayleigh scattering light, including: correlation principle of Rayleigh scattering light in optical fiber, 桅 -OTDR sensing principle and several existing 桅 -OTDR phase demodulation schemes. In this paper, based on 90. The phase demodulation method of Rayleigh scattering light for optical mixers is presented. The demodulation principle and the principle of 桅 -OTDR acoustic wave sensing based on this demodulation method are briefly described. In this paper, based on 90. The 桅 -OTDR phase demodulation experiment of heterodyne detection built by optical mixer shows that this demodulation scheme can realize the phase demodulation of Rayleigh scattering light in optical fiber, and the 桅 -OTDR based on this scheme can carry out distributed acoustic wave sensing. 4. In this paper, a 90. 0 based on homodyne detection is built. The 桅 -OTDR system of optical mixer, and the acoustic wave sensing experiment: using the MATLAB program and LABVIEW program written by ourselves, the acoustic disturbance experiment of off-line and on-line distributed acoustic wave sensing system is carried out, which is further proved to be based on 90. The feasibility of the phase demodulation scheme of the optical mixer is discussed. The flatness of the frequency response of the system and the linearity of the response of the system to different acoustic amplitudes are analyzed briefly. In this paper, the phase demodulation scheme based on 90 掳optical mixer and several other phase demodulation schemes are compared. It is concluded that 桅 -OTDR based on 90 掳optical mixer is stable and real-time in acoustic sensing. A conclusion of high sensitivity.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN253
【参考文献】
相关硕士学位论文 前1条
1 刘畅;3×3耦合器解调方法研究与实现[D];哈尔滨工程大学;2012年
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