微结构太赫兹波导的设计与特性分析
摘 要
太赫兹（THz）波是介于微波与可见光之间的电磁波，由于其在电磁波频谱中的特殊位置，所以 THz 波展现出了很多特殊的性质和应用的潜质。然而，大多数THz实验与THz系统是基于体积较大的、需要专业调整与对准且环境容易引起损耗的自由空间光学，会给应用带来一定的不便，因此需要研究制作合适的能用于低损耗THz波传输的波导。由于聚合物材料在THz波段具有吸收低、色散小等优良特性。因此开发具有低损耗的用于THz波传输的微结构聚合物光纤对THz波的传输技术将起到至关重要的作用。
本文以Topas COC材料为基质，将多孔型光纤与空气芯折射率引导型光纤相结合，设计了一种多孔芯光子折射率引导型微结构聚合物光纤。基于全矢量有限元法，分析了其有效折射率特性、限制损耗特性及有效材料吸收损耗特性。在材料低损耗的基础上，该微结构光纤的传输损耗进一步降低，此外，该光纤还具有平坦色散的优点。结果表明该微结构聚合物光纤可应用于远距离THz通讯技术领域。
关键词：太赫兹，聚合物，光子带隙型光纤，低损耗
Design and Characterization of Microstructured Terahertz Waveguides
ABSTRACT
Terahertz (THz) waves are electromagnetic waves between microwaves and visible light. Because of their special locations in the electromagnetic spectrum, THz waves exhibit many special properties and application potentials. However, most THz experiments and THz systems are based on large-volume free-space optics that require special adjustment and alignment, and the environment is prone to loss. This will cause some inconvenience to the application. Therefore, it is necessary to research and develop suitable ones. Waveguide for low-loss THz wave transmission. Because the polymer material has low absorption, small dispersion and other excellent characteristics in the THz wave band. Therefore, the development of micro-structured polymer optical fiber for THz wave transmission with low loss will play a crucial role in the transmission technology of THz wave.
In this paper, a porous core photon refractive index-guided micro-structured polymer optical fiber was designed based on Topas COC material and a porous optical fiber was combined with an air core refractive index-guided optical fiber. Based on the full vector finite element method, its effective refractive index characteristics, limiting loss characteristics and absorption characteristics of effective materials are analyzed. On the basis of low material loss, he transmission loss of the microstructured fiber is further reduced. In addition, the fiber also has the advantage of flat dispersion. The results show that the micro-structured polymer fiber can be applied in the field of remote THz communication technology.
Key words: Terahertz, polymer, photonic band gap fiber, low loss
目 录
摘 要 Ⅰ
ABSTRACT Ⅱ
1 绪论 1
1.1 太赫兹技术 1
1.2 太赫兹波导器件的研究 1
1.3 微结构光纤介绍 2
1.3.1 微结构光纤 2
1.3.2 微结构光纤的分类 3
1.3.3 微结构光纤的特性 5
1.3.4 微结构光纤的应用 7
1.4 太赫兹微结构聚合物光纤简介 7
1.4.1 太赫兹技术简介 7
1.4.2 太赫兹微结构光纤的发展现状 8
1.5 本课题的目的及意义 10
1.6 本文主要内容与结构安排 10
2 微结构聚合物光纤理论模型的研究方法 12
2.1 全矢量有限元法 12
2.1.1 基本原理 13
2.1.2 完美匹配层边界条件 13
2.2 COMSOL软件简介 14
2.3 小结 15
3 太赫兹多孔芯微结构聚合物光纤 16
3.1 多孔芯聚合物光纤结构设计 16
3.1.1 引言 16
3.1.2 微结构聚合物光纤理论模型 17
3.2 计算结果与讨论 17
3.2.1 有效折射率 18
3.2.2 限制损耗特性 18
3.2.3 有效材料吸收损耗特性 19
3.3 本节小结 20
4 总结与展望 21
4.1 本论文工作总结 21
4.2 未来研究展望 21
致 谢 22
参 考 文 献 23