十字架纖芯THz偏振分束器
Cross-core THz polarization splitter

19000字 41頁

目錄
中文摘要 6
ABSTRACT 7
1 緒論 8
1.1 課題的研究背景及意義 8
1.2 THz-PCF的概述 9
1.3 偏振分束器的概述 10
1.4 論文的主要工作 16
2 理論研究方法 18
2.1 COMSOL Multiphysics軟件及有限元法簡(jiǎn)介 18
2.2 Rsoft和光束傳播法簡(jiǎn)介 22
2.3 本章小結(jié) 24
3 十字架纖芯THz偏振分束器特性分析及設(shè)計(jì)思路 25
3.1 十字架纖芯THz偏振分束器的簡(jiǎn)介 25
3.1 .1 雙芯光纖的工作原理 25
3.1.2 十字架纖芯THz偏振分束器的性能指標(biāo) 26
3.2 十字架纖芯THz偏振分束器的設(shè)計(jì)思路 27
3.3 十字架纖芯THz偏振分束器的基本特性分析 28
3.3.1 十字架纖芯THz偏振分束器的結(jié)構(gòu) 29
3.3.2傳輸特性分析 32
3.4 本章小結(jié) 37
總結(jié)與展望 38
致謝 39
參考文獻(xiàn) 40

摘要： 在光通信領(lǐng)域中，偏振分束器是構(gòu)建全光網(wǎng)絡(luò)的一個(gè)重要器件。傳統(tǒng)偏振分束器的長(zhǎng)度較長(zhǎng)、分光比較低，也不利于制備。近些年來，太赫茲光子晶體光纖（THz-PCF）以其單模截止特性、零色散點(diǎn)可調(diào)等優(yōu)異特性引起人們的高度重視。本文基于THz-PCF的優(yōu)異特性，研究十字架纖芯THz光纖偏振分束器。文章使用矢量有限元方法設(shè)計(jì)偏振分束器的結(jié)構(gòu)，用全矢量光束傳播法分析其分束特性。
本論文設(shè)計(jì)的十字架纖芯THz偏振分束器，在光纖橫截面引入交叉介質(zhì)層，由于其基模模場(chǎng)能量主要分布在纖芯周圍的空氣孔中，從而實(shí)現(xiàn)了低的傳輸損耗。當(dāng)工作波長(zhǎng)為300μm時(shí)，數(shù)值計(jì)算結(jié)果表明該偏振分束器的分束長(zhǎng)度為12.16cm。在292—307μm波長(zhǎng)范圍內(nèi)，偏振分束器的消光比絕對(duì)值可高于15dB，且在300μm處，兩偏振模的器件傳輸損耗不超過0.3dB。
本論文提出的新型十字架纖芯THz光纖偏振分束器結(jié)構(gòu)簡(jiǎn)單，性能優(yōu)良，為THz光纖偏振分束器的設(shè)計(jì)提供了新的思路，在未來的相關(guān)應(yīng)用中將具有重要意義。
關(guān)鍵詞：偏振分束器 太赫茲 光子晶體光纖 超模

Cross-core THz polarization splitter
ABSTRACT： In the field of optical communications, polarizing beam splitter is an all-optical network is an important device. Traditional polarizing beam splitter longer length spectroscopic relatively low, is not conducive to the preparation. In recent years, terahertz photonic crystal fiber (THz-PCF) with its single-mode cutoff characteristics, zero dispersion point adjustable and other outstanding features attracted people's attention. Based on the excellent properties of the THz-PCF studied cross THz core fiber polarization beam splitter. Article vector finite element method using a polarization beam splitter design structure, with full vector beam propagation method to analyze the beam characteristics.
In this thesis, the core cross THz polarization beam splitter, the dielectric layer is introduced in the fiber cross cross-section due to its fundamental mode field distribution of energy in the main air holes around the core in order to achieve a low transmission loss. When the wavelength is 300μm, the calculation results show that the polarization beam splitting unit length of 12.16cm. In the wavelength range of 292-307μm, the polarization beam splitter may be greater than the absolute value of the extinction ratio of 15dB, and the place at 300μm, the transmission loss of the device is not more than two polarization mode 0.3dB.
This paper presents new cross core of THz fiber polarization beam splitter simple structure, excellent performance, as THz fiber polarization beam splitter is designed to provide new ideas, has important significance in the relevant application in the future.
KEYWORD：Polarization splitter;Terahertz;Photonic crystal fiber (PCF);Super mode