【作者】 麻硕；

【导师】 毕卫红；

【作者基本信息】 燕山大学 ， 电路与系统， 2011， 博士

【摘要】 光子晶体光纤(PCF)是一种新型特种光纤,其包层排列有周期性或随机性分布的微米量级的空气孔,使PCF在设计和制备上具有了更大的灵活性。通过在纤芯附近引入应力元,或者调整空气孔的尺寸和排列方式,均可以获得具有高双折射特性的PCF。与常规保偏光纤(PMF)相比较,高双折射PCF具有灵敏度更高、温度稳定性更好、保偏性能更好等优点,可广泛应用于光纤陀螺、光纤偏振干涉仪等光纤传感领域。本论文探索研究高双折射PCF的模间干涉特性及其在光学电压互感器中的应用,为光学电流/电压互感器的实现提供一种新的思路。本文详细介绍了高双折射PCF中双折射产生的原理及其在传感方面的应用现状,以及国内外光学电压互感器的基本工作原理及其研究发展现状,在此基础上,分析了高双折射PCF的模间干涉特性,并对基于高双折射PCF模间干涉的光学电压互感器进行了探索性研究。本文的主要研究内容如下:第一,采用有限元方法对双孔PCF、类矩形PCF以及六角芯PCF这三种不同结构的几何型高双折射PCF的模式特性进行分析,探索适合用于电压互感器的高双折射PCF。分析了三种PCF的模式双折射随波长的变化关系,以及各阶模式的截止波长,研究高双折射PCF的双模工作波长范围,并且以双孔PCF为例,讨论了光纤截面参数的变化对于模式双折射和模场半径的影响。第二,对椭圆芯PMF、双孔PCF和类矩形PCF的模间干涉特性进行了仿真研究,比较分析了这三种光纤的模式截止特性及其模间干涉灵敏度、干涉场的模场特性随波长的变化规律,证明高双折射PCF更适于基于模间干涉的光学电压互感器。第三,研究了双孔PCF的结构参数对模间干涉特性的影响,分析了不同结构参数双孔PCF的双模传输波长范围以及模间干涉灵敏度随波长的变化规律,探索研究了适合用于模间干涉的双孔PCF的结构参数。第四,对基于高双折射PCF模间干涉的光学电压互感器基本传感性能进行了实验研究和分析。通过实验观测双孔PCF的模间干涉现象,分别采用直接拉伸调制光纤长度和通过压电陶瓷调制光纤长度两种实验方法对双孔PCF模间干涉灵敏度进行了测量。对利用压电陶瓷和双孔PCF实现的基于模间干涉原理和逆压电效应的低电压传感系统进行了实验研究,对利用石英晶体逆压电效应和双孔PCF模间干涉原理的高压互感器进行了可行性实验研究,并对实验结果进行了分析和讨论。更多还原

【Abstract】 Photonic Crystal Fiber (PCF) is a new special type of optical fibers. The periodical or random arrangement of micrometer-scale air holes running along the full length of the fiber in the cladding region brings flexibility for the design and fabrication of fiber. Highly birefringence can be obtained by introducing the stress-applying parts into the core or changing the dimension and location of the air holes of PCF. Compared with the conventional polarization maintaining fiber (PMF), highly birefringent PCF (HB-PCF) has many advantages, such as the higher sensitivity, the better temperature stability and the better ability of polarization maintaining, which make it apply to a wide range field related with optical fiber sensing. This paper researches the modular interference characteristics of HB-PCF, and applies HB-PCF to optical voltage transducer (OVT), providing a novel thought to optical voltage and current transducer.This paper introduces the principles and the applications in HB-PCF sensing. Referring to the development status, basic theory of OVT in the world, the modular characteristics of HB-PCF is analyzed, and an OVT based on HB-PCF is proposed and studied theoretically and experimentally. The main contents are as follows:First, the mode properties of two-hole PCF, near-rectangle PCF and hexagonal core PCF are analyzed using finite-element method in order to find the proper HB-PCF used for OVT. The dependence of modal birefringence on the wavelength, the cut-off wavelength of guided modes and the wavelength range for two-mode operation are researched. Taking two-hole PCF as the example, the effects of structural parameters on modal birefringence and mode field radius are discussed.Second, the modular interference characteristics of elliptical core PMF, two-hole PCF and near-rectangle PCF are simulated. The cut-off wavelength of guided modes, the dependence of the modular interference sensitivity and mode field properties on wavelength are compared. The results show that HB-PCF is more suitable for OVT.Third, the effects of structural parameters on modular interference in two-hole PCF are discussed. The wavelength range for two-mode operation, the relationship between the modular interference sensitivity and wavelength in two-hole fiber with different structure parameters are analyzed. The optimal structure of two-hole PCF for modular interference is designed.Fourth, the experimental system of PCF OVT based on modular interference is set up. The phenomena of modular interference about two-hole PCF are observed. The modular interference sensitivity of two-hole PCF is measured when the fiber’s length is changed by tensing or using the converse piezoelectric effect of PZT. The low voltage sensor system based on PZT and the high voltage sensor system based on quartz crystal are researched experimentally. The results are analyzed and discussed.更多还原