摘要
近幾年來極化維持光纖已被廣泛的討論與研究，從早期的壓力式雙折射光纖演進到進期較為新穎的極化維持光子晶體光纖，不僅提升了雙折射的效率，更增加了許多優點，例如加大了模態面積及具備大頻寬的單模傳輸。在本論文中，我們提出了在光子晶體光纖中以不對稱的方式填入液體來設計一個可調式的雙折射液體填入光子晶體光纖。我們使用了一個有完美匹配層的有限差分頻域法來分析液體填入式的雙折射光子晶體光纖，成功\\\地分析出液體填入光子晶體光纖後的光學特性，其雙折射效益與傳統的極化光纖相比提升了數倍，在波長1.55 μm時可達到7.1 × 10-3的高度雙折射性，並且具備了可調的光電特性。
而在實驗的部份，我們引進了光子晶體光纖的封孔和校準的技術，在光子晶體光纖的兩側做封塞的動作，再以真空的方式將液體順利地填入光子晶體光纖中，成功地製作出雙折射液體填入光子晶體光纖。而我們也對該光纖作初步的遠場量測，在文中我們也會展示實驗的量測架構與未來努力的方向。

Polarization-maintaining fibers (PMFs) have been widely studied and discussed. Nowadays, a novel polarization-maintaining photonic crystal fiber (PMPCF) is proposed with many advantages, such as the large mode area and the single-mode transmission in a wide frequency range. In this thesis, we propose the birefringent liquid-filled PCF with the liquid asymmetrically infiltrated in the cladding region. The Yee-mesh-based finite-difference frequency-domain (FDFD) method is utilized to analyze the birefringent properties of the liquid-filled PCFs. Compared with traditional PMFs, our proposed PCF possesses larger birefringence about 7.1 × 10-3 at 1.55 μm with useful tunable properties.
In the experiment, we have successfully fabricated the birefringent liquid-filled PCF by using the selective blocking technique. The elliptical far field can be observed for our birefringent PCF. We also demonstrate the experiment setup for estimating the birefringence of our birefringent liquid- filled PCF.

1 Introduction
1.1 Motivations 1
1.2 Chapter Outline 4

2 Numerical Methods
2.1 Overview 11
2.2 Formulae of the FDFD Method 11
2.3 FDFD Method with PMLs 15
2.4 Index Averaging Method 20

3 Numerical Results of Birefringent Liquid-Filled Photonic CrystalFibers 25
3.1 Overview 25
3.2 Highly Birefringent Liquid-Filled PCFs 26
3.3 Loss-Reduced Birefringent Liquid-Filled PCFs30

4 Fabrication and Measurement of Birefringent Liquid-Filled Photonic Crystal Fibers
4.1 Fabrication 48
4.1.1 Tool Fiber and UV gel 49
4.1.2 Alignment Setup 49
4.1.3 Blocking Technique 50
4.1.4 Vacuum Filling Setup 50
4.2 Measurement
4.2.1 Experiment Setup 51
4.2.2 Measurement Result 52
4.2.3 Future work 53

5 Conclusions 66

Bibliography 67

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