一种新型RBOTDA传感系统的研究
发布时间：2019-07-10 09:02
【摘要】：本文综述了分布式布里渊光纤传感技术近年来的研究现状。介绍了基于布里渊散射的分布式光纤传感技术中的布里渊光时域反射(BOTDR)和布里渊光时域分析(BOTDA)传感技术的原理,并分析了传统的基于瑞利散射的布里渊光时域分析(RBOTDA)的传感原理及其特点。对RBOTDA系统中EOM工作点的原理进行了分析,并仿真研究了EOM工作在传输曲线的谷点与线性点时各阶光强分布情况,得出将EOM的偏置端锁定在谷点工作点时得到的1阶光波的信噪比最大。因此,提出了两个EOM并联的结构产生RBOTDA传感系统所需的含脉冲基底的脉冲光,探测光由基底连续光产生的瑞利散射提供。提出了一种新型的RBOTDA系统结构。该系统工作在单端,能克服传统BOTDA双端接入的缺点。详细阐述了新型RBOTDA系统的结构,对系统中非本地效应的产生机理进行了详细的建模分析,并提出了解决非本地效应的方法。在传感过程中使用双边带探测光,有效地补偿泵浦耗尽,减少非本地效应带来的失真影响。通过分析平衡检测器抑制共模噪声的原理,在检测端使用平衡探测器,消除共模噪声的同时改善系统的信噪比。搭建了RBOTDA实验系统。实验结果表明:布里渊增益谱完好地贴合洛伦兹曲线,非本地效应得到了有效的抑制;在2.4km光纤上,室温25℃下泵浦脉宽50ns时,布里渊频移为10.867GHz,布里渊线宽约为40.21MHz;对系统进行了平衡检测与非平衡检测的对比实验研究和分析,得出平衡检测输出的噪声功率是单独stokes或者anti-stokes的2~（1/2）倍,平衡检测输出的信噪比提高了2~（1/2）倍;光纤末端布里渊谱中平衡检测的布里渊频谱图与布里渊增益型或损耗型相比频谱线更平滑,噪声较小。
文内图片：
图片说明：谷点调制后的光谱图
[Abstract]:In this paper, the research status of distributed Brillouin optical fiber sensing technology in recent years is reviewed. The principle of Brillouin optical time domain reflection (BOTDR) and Brillouin optical time domain analysis (BOTDA) sensing technology based on Brillouin scattering is introduced, and the sensing principle and characteristics of traditional Brillouin optical time domain analysis (RBOTDA) based on Brillouin scattering are analyzed. The principle of EOM working point in RBOTDA system is analyzed, and the distribution of light intensity of each order when EOM works at valley point and linear point of transmission curve is studied by simulation. It is concluded that the signal-to-noise ratio (SNR) of the first order light wave obtained by locking the bias end of EOM at the working point of valley point is the largest. Therefore, two EOM parallel structures are proposed to generate the pulse light with pulse substrate needed by the RBOTDA sensing system, and the detection light is provided by the Rayleigh scattering produced by the continuous light of the substrate. A new RBOTDA system structure is proposed. The system works on a single end and can overcome the shortcomings of traditional BOTDA dual-terminal access. The structure of the new RBOTDA system is described in detail, the mechanism of non-local effect in the system is modeled and analyzed in detail, and the method to solve the non-local effect is put forward. In the sensing process, the bilateral band probe light is used to effectively compensate the pump depletion and reduce the distortion effect caused by the non-local effect. By analyzing the principle of common mode noise suppression by balance detector, the balance detector is used at the detection end to eliminate the common mode noise and improve the signal to noise ratio of the system at the same time. The RBOTDA experimental system is built. The experimental results show that the Brillouin gain spectrum fits the Lorentz curve perfectly and the non-local effect is effectively suppressed. On 2.4km fiber, the Brillouin frequency shifts to 10.867GHz and Brillouin linewidth is about 40.21MHz when pumping pulse width 50ns at room temperature of 25 鈩，
本文编号：2512497
文内图片：
图片说明：谷点调制后的光谱图
[Abstract]:In this paper, the research status of distributed Brillouin optical fiber sensing technology in recent years is reviewed. The principle of Brillouin optical time domain reflection (BOTDR) and Brillouin optical time domain analysis (BOTDA) sensing technology based on Brillouin scattering is introduced, and the sensing principle and characteristics of traditional Brillouin optical time domain analysis (RBOTDA) based on Brillouin scattering are analyzed. The principle of EOM working point in RBOTDA system is analyzed, and the distribution of light intensity of each order when EOM works at valley point and linear point of transmission curve is studied by simulation. It is concluded that the signal-to-noise ratio (SNR) of the first order light wave obtained by locking the bias end of EOM at the working point of valley point is the largest. Therefore, two EOM parallel structures are proposed to generate the pulse light with pulse substrate needed by the RBOTDA sensing system, and the detection light is provided by the Rayleigh scattering produced by the continuous light of the substrate. A new RBOTDA system structure is proposed. The system works on a single end and can overcome the shortcomings of traditional BOTDA dual-terminal access. The structure of the new RBOTDA system is described in detail, the mechanism of non-local effect in the system is modeled and analyzed in detail, and the method to solve the non-local effect is put forward. In the sensing process, the bilateral band probe light is used to effectively compensate the pump depletion and reduce the distortion effect caused by the non-local effect. By analyzing the principle of common mode noise suppression by balance detector, the balance detector is used at the detection end to eliminate the common mode noise and improve the signal to noise ratio of the system at the same time. The RBOTDA experimental system is built. The experimental results show that the Brillouin gain spectrum fits the Lorentz curve perfectly and the non-local effect is effectively suppressed. On 2.4km fiber, the Brillouin frequency shifts to 10.867GHz and Brillouin linewidth is about 40.21MHz when pumping pulse width 50ns at room temperature of 25 鈩，
本文编号：2512497
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