Design and Analysis of Photonic Crystal Waveguides for Communication Applications

• Main Authors: Jian-Jang Lee, 李建樟
• Other Authors: Yaw-Dong Wu
• Format: Others
• Language: en_US
• Published: 100
• Online Access: http://ndltd.ncl.edu.tw/handle/57752262584468440345

博士 === 國立高雄應用科技大學 === 電子工程系 === 100 === We utilize two-dimensional (2D) periodic array of photonic crystals (PCs) formed an optical waveguide to guide the light propagations. One of important property is photonic band gap (PBG) in the PCs. The PBG can be forbidden or transmitted an electromagnetic wave at certain frequency by introducing defect in periodic dielectric structure. Hence, we utilize these characteristics to develop novel devices for communication applications. This dissertation reports on two kinds of PC structures: The first kind is planar lightwave circuit (PLC), a new design of photonic crystal ring resonator (PCRR) filter which consists of an array of dielectric rods. The analysis used finite difference time domain (FDTD) method and plane wave expansion (PWE)method to simulate their properties. In order to efficiently separate wavelengths, we further used PCRR integrated with directional coupler. The numerical results demonstrate the effective separation of 1.31um, 1.49um, and 1.55um. In order to achieve more wavelengths, we cascade more ring-resonators and the numerical results show the scales linearly variation. This study also develops a 16-channel dense wavelength division multiplexer (DWDM). The second kind is photonic crystal fiber (PCF). The properties of PCFs are calculated the effective index, mode field diameter (MFD), confinement loss, at fundamental mode by using finite element method (FEM). Then the different diameter and pitch of air-hole are discussed and analyzed. In this study, we proposed single-mode PCF with ultralow confinement loss and effective mode area of 1400um2 at 1.064um. Meanwhile, we study the birefringence property of PCFs to design a polarization-maintaining PCF. First the PCF places large holes on the opposite sides of the core, which can induce the different indices in x- and y-directions. In order to obtain higher birefringence, we further introduce elliptical holes. It is found that increasing the number of rings can reduce the confinement loss and increase the birefringence. Finally, the different hole pitch is discussed when hole pitch is smaller than 2um, which can achieve the birefringence of 10-2 order. In this study, large mode area (LMA) and high birefringence of PCFs are proposed and they can further apply to high power delivering and sensing system.