【作者】 吴桂峰；

【导师】 陈鹤鸣；

【作者基本信息】 南京邮电大学 ， 光学工程， 2011， 硕士

【摘要】 光纤技术是信息技术领域的重要前沿,光子晶体光纤是基于光子晶体技术发展起来的新一代光纤,它具有传统光纤所无法比拟的光学性质,如无截止单模传输、灵活的色散特性、可控的非线性、以及高双折射效应等。近年来,基于光子晶体光纤的压力传感器已成为研究的热点。本文首先提出了一种新型高双折射光子晶体光纤,该光纤包层为二氧化硅介质中按三角形格子排列的空气孔,在纤芯中心移去空气孔,而在芯区上下各引入2个大空气孔,并在芯区填入聚碳酸酯。然后应用平面波展开法分析了这种保偏光子晶体光纤的模式和双折射,并对该种光纤结构参数进行了优化。结果表明,提高近芯区大空气孔直径可以有效提高双折射。在此基础上,用有限元方法研究了横向压力对光子晶体光纤传输特性的影响。结果表明,横向压力使光子晶体光纤的双折射发生变化,从而导致入射线偏振光X,Y两个偏振传输模式的相位差发生变化,通过检测偏振光两个方向的相位差就可以感知到外界环境压力的变化大小。本文还通过改变光纤的结构参数来分析光子晶体光纤双折射随压力变化的影响因素,通过一系列的仿真对比得到压力敏感度最大的光纤结构参数。最后,设计了一种基于双折射光子晶体光纤的压力传感器,并对该传感器具体结构组成和材料参数选择进行了讨论,通过对比已有的几种干涉型光子晶体光纤压力传感器,分析了本文提出的压力传感器的优缺点,介绍了双折射光子晶体光纤压力传感器在智能安全监测中的应用。更多还原

【Abstract】 Optical fiber technology is an important frontier area of information technology, Photonic Crystal Fibers is a new generation of optical fiber developed based on photonic crystal technology. It have the optical property what the traditional fiber can’t compared with, such as free single mode transmission, controlled dispersion, high birefringence and can be modified micro-structural design and so on. In recent years, photonic crystal fiber sensor has become a research hotspot.In this paper, a new type of high birefringence photonic crystal fiber is proposed. The cladding of the fiber is made of silica dioxide medium with air holes arranged as triangular lattice, two large air holes are introduced both above and below the core area, and the core area is filled with Polycarbonate (PC). First of all, the mode and the birefringence of the polarization-maintaining photonic crystal fiber are analyzed by plane wave expansion method, and the influence of structural parameters of the fiber on the birefringence is researched. Results show that the enlargement of large air hole diameter can effectively enhance the birefringence.Based on the study of the birefringence properties of photonic crystal fiber, Finite element method was used to analyze the pressure affecting on the photonic crystal fiber transmission characteristics. The results showed that the birefringence of photonic crystal fiber was changed by the pressure what leading to the phase of two polarization modes changed, the pressure sensing can be achieved by the measurement of phase. By analysing the factors of pressure sensor with changing the structural parameters, we obtained the fiber structural parameters of Large pressure sensitivity through a series of simulations.Finally, a photonic crystal fiber pressure sensor was designed, and the specific structure of the sensor components and material parameters were discussed.The advantages and disadvantages of the pressure sensor were analyzed by comparing several existing photonic crystal interferometric fiber pressure sensor.Pressure sensors in environmental monitoring applications were introduced at last.更多还原