光纤声光可调谐滤波器的特性研究及应用

发布时间：2018-09-12 08:16

【摘要】：随着通信领域逐渐步入全光纤网络时代,飞速发展的光纤通信系统对光纤滤波器的性能提出了更高的要求,研制出结构简单、调谐范围宽、调谐速度快的光纤可调谐滤波器成为了必然。本论文针对光纤声光可调谐滤波器展开系统的研究和分析,将光纤声光可调谐滤波器应用于光纤传感领域,提出了基于单模光纤型声光可调谐滤波器的光纤激光应变传感系统和基于单模光纤型声光可调谐滤波器的光纤布拉格光栅解调系统。论文的主要研究成果如下：1.分析了单模光纤型声光可调谐滤波器的轴向应变和温度特性,滤波器的谐振波长随着轴向应变或温度的增加呈线性增长趋势,且光纤包层直径越小的滤波器的谐振波长随轴向应变或温度的增长系数越大；实验测试了光纤包层直径分别约为39μmm和67μm的单模光纤型声光可调谐滤波器的轴向应变和温度特性,实验结果的变化趋势与仿真结果基本一致。2.提出了一种基于单模光纤型声光可调谐滤波器的光纤激光应变传感系统,在光纤激光应变传感系统中,单模光纤型声光可调谐滤波器作为带阻滤波器和传感头,该系统结合了单模光纤型声光可调谐滤波器对轴向应变具有线性的、高灵敏度的响应和光纤激光器较高的信噪比、较窄的线宽的优势,该系统的激光输出波长随着轴向应变的增加呈线性增长趋势,其灵敏度高达0.148nm/με,高于大多数其它类型的光纤轴向应变传感器。3.提出了一种基于单模光纤型声光可调谐滤波器的光纤布拉格光栅解调系统,该系统利用了单模光纤型声光可调谐滤波器的传输光谱的带阻滤波特性,通过测量经过单模光纤型声光可调谐滤波器后的光纤布拉格光栅的反射光谱的峰值功率,可以得到轴向应变的大小,同时,通过控制信号发生器的输出电压幅值,可以实现基于单模光纤型声光可调谐滤波器的光纤布拉格光栅解调系统的响应度的调谐。4.理论分析了均匀光纤布拉格光栅型和高斯切趾光纤布拉格光栅、相移光纤布拉格光栅和啁啾光纤布拉格光栅三种非均匀光纤布拉格光栅型声光可调谐滤波器的传输特性,建立相关的理论模型,分析了声波频率和声致应变幅度对均匀光纤布拉格光栅型和非均匀光纤布拉格光栅型声光可调谐滤波器的传输特性的影响；实验测试了声波频率分别为563kHz和885.5kHz的基于剪切型PZT的均匀光纤布拉格光栅型声光可调谐滤波器的传输光谱和声波频率分别为390kHz和700kHz的基于普通PZT的均匀光纤布拉格光栅型声光可调谐滤波器的传输光谱,实验发现两者的传输特性较为相似,且变化趋势与仿真结果基本一致。5.提出了一种光纤叠栅型声光可调谐滤波器,建立了相关的理论模型,理论分析了声波频率和声致应变幅度对光纤叠栅型声光可调谐滤波器的传输特性的影响,实验测试了声波频率分别为390kHz和710kHz的光纤叠栅型声光可调谐滤波器的传输光谱,实验结果的变化趋势与仿真结果基本一致。
[Abstract]:With the rapid development of optical fiber communication system, it is necessary to develop a tunable fiber filter with simple structure, wide tuning range and fast tuning speed. This paper focuses on the research of optical fiber acoustooptic tunable filter. The fiber optic acousto-optic tunable filter is applied to the fiber sensing field. The fiber optic strain sensing system based on single-mode fiber acousto-optic tunable filter and fiber Bragg grating demodulation system based on single-mode fiber acousto-optic tunable filter are proposed. The main research results are as follows: 1. The axial strain and temperature characteristics of fiber-optic acoustooptic tunable filter show that the resonant wavelength of the filter increases linearly with the increase of the axial strain or temperature, and the resonant wavelength of the filter with smaller fiber cladding diameter increases with the increase of the axial strain or temperature coefficient. Axial strain and temperature characteristics of a single-mode fiber-optic acousto-optic tunable filter at 67 micron are presented. The experimental results are in good agreement with the simulation results. 2. A fiber-optic laser strain sensing system based on single-mode fiber-optic acousto-optic tunable filter is proposed. In fiber-optic laser strain sensing system, single-mode fiber-optic acousto-optic tunable filter is used. As a band-stop filter and sensor head, the system combines the advantages of single-mode fiber-optic acoustooptic tunable filter with linear axial strain, high sensitivity response, high signal-to-noise ratio and narrow linewidth of fiber laser. The output wavelength of the system increases linearly with the increase of axial strain, and its sensitivity is high. A fiber Bragg grating demodulation system based on single-mode fiber-optic acoustooptic tunable filter is proposed. The system utilizes the band-stop filtering characteristics of the transmission spectrum of single-mode fiber-optic acoustooptic tunable filter by measuring the band-stop filtering characteristics of the transmission spectrum of the single-mode fiber-optic tunable filter. The peak power of the reflection spectrum of fiber Bragg grating after the fiber-optic acoustooptic tunable filter can obtain the magnitude of axial strain. At the same time, the response of fiber Bragg grating demodulation system based on single-mode fiber-optic acoustooptic tunable filter can be tuned by controlling the output voltage amplitude of the control signal generator. The transmission characteristics of homogeneous fiber Bragg grating and Gaussian apodized fiber Bragg grating, phase-shifted fiber Bragg grating and chirped fiber Bragg grating acousto-optic tunable filters are analyzed theoretically. Relevant theoretical models are established, and the effects of acoustic frequency and acoustic strain amplitude on homogeneity are analyzed. The transmission characteristics of fiber Bragg grating (FBG) and non-uniform fiber Bragg grating (FBG) type acousto-optic tunable filters are investigated. The transmission spectra and acoustic frequencies of the uniform FBG type acousto-optic tunable filters based on shearing PZT are measured at 563 kHz and 885.5 kHz, respectively, 390 kHz and 700 kHz, respectively. Based on the transmission spectrum of uniform fiber Bragg grating acousto-optic tunable filter with ordinary PZT, it is found that the transmission characteristics of the two filters are similar, and the changing trend is basically consistent with the simulation results. The influence of strain amplitude on the transmission characteristics of fiber-optic acousto-optic tunable filters with stacked gratings is investigated. The transmission spectra of fiber-optic acousto-optic tunable filters with the acoustic frequencies of 390 kHz and 710 kHz are measured experimentally. The experimental results are in good agreement with the simulation results.
【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN713

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