近年來，越來越多不同類型的干涉儀被提出並且廣泛地討論，利用其干涉的特性，干涉儀可以應用在許多不同領域。在本論文中，我們利用錯位融接的方式，製作光子晶體光纖式干涉儀，其原理是將單模光纖以及光子晶體光纖融接在一起時，利用纖心的錯位融接，激發出纖心模態以及纖衣模態。此兩種模態以不同速度在光子晶體光纖中傳遞，在第二個融接點時，兩個模態又重新結合並傳遞至單模光纖中，利用兩模態在光子晶體光纖傳遞過程中所累積之相位差來產生干涉的現象。由量測結果我們發現，光子晶體光纖長度會影響到我們所觀察到的干涉現象，當長度增加時，相位差增加，干涉條紋間的間距會縮小，這跟其他文章的結果是相符合的。證明了我們成功\地利用錯位融接的方式製作出光子晶體光纖式干涉儀。
我們利用此光子晶體光纖式干涉儀進行溫度、曲率半徑、外在環境折射率的感測，觀察干涉現象的改變，並計算此干涉儀對這些外在參數之靈敏度。由測量結果得知我們所製作的光子晶體光纖式干涉儀對溫度是非常不敏感的，因此可以在高溫下應用。此外，當我們改變外在環境折射率從1.404增加至1.428時，干涉頻譜會往長波長移動並呈現指數型的關係，所以我們可以將此元件拿來當作外在環境感測器使用。此外，我們還製作了液體填充光子晶體光纖式干涉儀，並且進行外在環境折射液及曲率半徑的量測，此元件對曲率半徑的靈敏度可以達到8.5nm/m-1。另外，當我們進行外在環境折射率的量測時，有填充折射液的光子晶體光纖干涉儀會比沒填充折射液的干涉儀來的不敏感，故我們發現此類型的干涉儀也是非常適合拿來當作感測器的。

We propose a PCF-based interferometer by the misaligned splicing method. The PCF-based interferometers are composed of a photonic crystal fiber (PCF) and single-mode fibers (SMFs) which are spliced with lateral offsets. As the wave propagates at the first splicing point, the lateral offset will excite the cladding mode and the core mode simultaneously. As the two modes reach the other splicing point, they are recombined and coupled into another SMF. Thus, we can observe the interference pattern resulted from the phase difference between the two modes. In addition, as the length of PCF is increased, the average splicing of the interference fringes become smaller in the same measured range.
We demonstrate the applications of the PCF-based interferometer as temperature, bending, and the surrounding refractive index sensors. The temperature sensitivity for the 2-cm and 4-cm PCF-based-interferometer is 3.9.~4.3pm/°C and 3.5~4.3pm/°C, respectively. As we increase the surrounding refractive index, the curves move toward longer wavelengths. Besides, the measured bending sensitivity of the PCF-based interferometer is 3.8~4.2nm/m-1.
We also fabricated the liquid-filled-PCF-based interferometers by using the vacuum filling method. The measured bending sensitivity of the liquid-filled-PCF-based interferometer is 8.5nm/m-1 which is higher than that of the PCF-based interferometer. The measured surrounding refractive index sensitivity is insensitive. Thus, this liquid-filled-PCF-based interferometer can also be utilized as a sensor.

1 Introduction 1
1.1 Photonic Crystal Fiber . . . . . . . . . . 1
1.2 interferometer . . . . . . . . . . . . . . 2
1.3 Chapter Outline . . . . . . . . . . . . . . 5
2 Theory and Fabrication of PCF-based
Interferometers 12
2.1 Overview . . . . . . . . . . . . . . . . . 12
2.2 Theoretical Analysis . . . . . . . . . . . . 12
2.3 PCF-based Interferometer by Misalignment
Method . . . . . . . . . . . . . . . . . . 15
2.4 Vacuum Filling Method . . . . . . . . . . 16
3 Experimental Results of PCF-based
Interferometers . . . . . . . . . . . . . . 24
3.1 Overview . . . . . . . . . . . . . . . . . . 24
3.2 Measurement Setups and Results of
PCF-based interferometer . . . . . . . . 24
3.3 Temperature Sensing Property. . . . . . 25
3.4 Surrounding Refractive Index Sensing
Property . . . . . . . . . . . . . . . . . . . 27
3.5 Bending Sensing Property . . . . . . . . 28
4 Experimental Results of Liquid-Filled-
PCF-Based Interferometers 44
4.1 Overview . . . . . . . . . . . . . . . . . . . 44
4.2 Interference Properties of Liquid-Filled-
PCF- Based Interferometers. . . . . . . . 44
4.3 Surrounding Refractive Index Sensing
Property . . . . . . . . . . . . . . . . . . . 45
4.4 Bending Sensing Property . . . . . . . . . 46
5 Conclusions 55
Bibliography 57

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