Calculation for Photonic Band Structure and Interpretation by Metamaterials Transmission Line

• Main Authors: Da-Wei Yeh, 葉大為
• Other Authors: Chien-Jang Wu
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/03512244947440843477

碩士 === 國立臺灣師範大學 === 光電科技研究所 === 97 === In this thesis, the thickness-dependent photonic bandgap for a one-dimensional photonic crystal consisting of two different single-negative materials is theoretically investigated. The two single-negative (SNG) materials include one with a single-negative permittivity and the other having a single-negative permeability. It is found that the size of the bandgap and the positions of the bandedges are strongly dependent on the thickness ratio of the two constituent SNG layers. Then, we also consider about in loss case effective for bandgap. Moreover, the angular dependence of the photonic band structure of a single-negative one-dimensional photonic crystal is theoretically investigated. To use the same photonic crystal structure, we discussed two propagation mode, which are TE mode and TM mode, for different incident angle. We use the concept of impedance matching to discuss the bandgap shift, thus the gap size with incident angle had been described clearly. Additionally, the characteristic frequency determined by the condition of impedance match is closely related to the center frequency of the bandgap in TE mode and TM mode. We used the parameter by ratio of the wavenumber on two medium, which is the wavenumber ratio of the two materials, to successfully explain angle varition and thickness-dependent bandgap and the bandedges for two polarization modes.