The Study of Beam-Splitter Devices in Two-Dimensional Photonic Crystals

• Main Authors: ZI-NING MAO, 毛子寧
• Other Authors: YAW-DONG WU
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/40632243823869285317

碩士 === 國立高雄應用科技大學 === 電子與資訊工程研究所碩士班 === 95 === In this thesis, it discussed the application of beam-splitter in the photonic crystals. A photonic crystal is a revolutionary class of artificially periodic electromagnetic media, in which a fundamentally new electromagnetic phenomenon can be achieved. A photonic band gap defines a range of frequencies for which light is forbidden to exist inside the crystal. In such beam-splitter, the optical field is confined, horizontally, by a photonic band gap (PBG) provided by the photonic crystal. By using plane-wave expansion method and finite-difference time-domain method to analyzed photonic crystal beam-splitter structure. Firstly, using the beam-splitter effect by varying the size of the airholes of the splitting structure, we present that the bending and controllable splitting of self-collimated beams can be useful in one-to-three beam splitter based on photonic crystals. Then, we have proposed an exquisite two-dimensional polarizing beam-splitter design with acceptable efficiency by utilizing the beam-splitting structure of the dispersion relationship inside and outside the PBG. The dielectric polarizing beam-splitter operates in PBG mode for both polarizations. Beside, by properly controlling the phase difference between the two input beams, we propose a new all-optical switch based on PCs. Finally, combining beam-splitting structure and mirror, it can establish PCs Michelson and Mach-Zehnder interferometers. Moreover, we integrate optical switches and interferometer into 2×2 Mach-Zehnder interferometer. Beside, combining the three characteristic of beam-splitting structure (transmission, reflection and equally-distributive power) and interferometer effect, we propose a new type of all-optical device for 1×3 router. The numerical results show that the proposed device could really function as an all-optical router. These would be a potential key component in the applications of ultra-high-speed and ultra-high-capacity optical communications and optical data processing systems. Deciding that the nanofabrication improves gradually, it will demonstrate a practical breakthrough for the realization of devices based on the photonic crystal integrated circuits.