【作者】 王雯；

【导师】 彭江得；

【作者基本信息】 清华大学 ， 电子科学与技术， 2009， 硕士

【摘要】 Bragg光纤是一种具有一维光子晶体包层的新型光子带隙导引光纤,它在结构特征、导光机制和传输特性上与传统光纤完全不同,可以极大的拓展光导纤维的应用领域,具有重要的应用前景。本论文工作结合国家973项目“微结构光纤基本理论和基本特性的探索与研究”和北京市自然科学基金项目“基于全向布拉格反射的新型空心光子带隙光纤”,研究中红外传输空心Bragg光纤的结构设计和工艺实现,并对Bragg光纤器件化应用进行了理论探索。论文综合比较了现有Bragg光纤制备工艺和材料系选择的特点,选取半导体玻璃(硒化砷)和有机聚合物(聚醚酰亚胺)作为基本材料系,预制棒熔拉法作为基本工艺方法进行中红外传输空心Bragg光纤样品制备研究。结合工艺路线给出了3～5微米波段和10.6微米波段两种中红外传输空心Bragg光纤及其预制棒的结构参数设计,并分析了关键工艺参数—硒化砷蒸镀层厚和光纤拉丝比—对导波特性的影响。建立了半导体玻璃-有机聚合物Bragg光纤的光纤拉丝工艺平台,并对此类光纤的拉丝工艺进行了实验研究,制备出国内首根Bragg光纤样品。傅立叶红外光谱测量表明Bragg光纤样品呈现明显的带隙导光特性,实验验证了Bragg光纤制备工艺平台和工艺路线的可行性。提出并理论验证了一种基于Bragg光纤双锥的新型三维限制光学微腔。理论证实了利用Bragg光纤导波模式带隙内截止的特性,Bragg光纤双锥可以实现光纤反射镜的功能。利用FDTD方法对两个Bragg光纤双锥构成的F-P腔结构进行了理论研究,证实该结构可以形成三维限制光学微腔,腔模理论Q值高达106。更多还原

【Abstract】 Bragg fiber is a novel Photonic-Bandgap fiber with one dimensional photonic crystal (1-D PC) cladding. Comparing to traditional optical fibers, its structure characteristics, light-guiding mechanism and transmission properties are quite different, leading to a wide expansion of optical fibers’applications.This paper devotes to the design and fabrication of hollow-core Bragg fibers for mid-infrared transmission, and theoretically explores the applications of Bragg-fiber-based devices, with the support of the 973 National Basic Research Program of China“Research on basic principles and characteristics of micro-structure fibers”and the program of Beijing Natural Science Foundation“Hollow bandgap-guiding fibers based on omni-direction Bragg reflections”.By comprehensively evaluating the characteristics of current fabrication technologies of Bragg fibers, the material pair of PEI and As2Se3 and fabrication technique of preform drawing are chosen to realize hollow-core Bragg fibers for mid-infrared transmission. Based on the fabrication process, the structure parameters of two kinds of mid-infrared transmitting Bragg fibers and their preforms are theoretically designed, aiming at 3~5μm and 10.6μm, respectively. The influences of light-guiding characteristics by the key fabrication parameters are analyzed, including the evaporation thickness of As2Se3 film and the preform-fiber drawing ratio.The fiber drawing platform for semiconductor-polymer based Bragg fibers is established. Corresponding fiber drawing technique is experimentally studied and the very first Bragg fiber sample in China is successfully fabricated. The FTIR measurement of the fiber sample shows apparent photonic-bandgap guiding effects, which demonstrates the feasibility of fiber fabrication platform and technique.A novel 3-D micro-cavity based on double Bragg fiber dual-tapers is proposed. The principle and characteristics of the Bragg fiber dual-taper are analyzed numerically. It shows that thanks to the abnormal in-band cutoff characteristics of the Bragg fiber, the dual-taper can be looked as a fiber mirror in the band between the cutoff frequencies of the tapered and untapered regions. Then, an F-P micro-cavity with two Bragg fiber dual-tapers as the mirrors is investigated by the FDTD method. Its 3-D light confinement is demonstrated and a cavity mode Q factor up to 106 is theoretically realized.更多还原