The Extraordinary Transmission through Periodic U- and H-shaped Hole Arrays

• Main Authors: Hao-Fu Huang, 黃浩菔
• Other Authors: 李嗣涔
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/10414439832473089225

碩士 === 國立臺灣大學 === 電子工程學研究所 === 98 === The extraordinary transmission through a metal film perforated with periodic U and H shape hole array in far-infrared region are demonstrated. In first part of this thesis, U-shaped hole is used to studied the transmission when the resonance length of the hole exceed the hole period. The longer rectangular hole can be design in the fixed period by ‘bending’ the rectangle into U shape. The influence of hole shape and hole size are demonstrated. For the sample with rectangular or U-shaped hole, the transmission mechanism is not always dominated by surface plasmon (SP).The localized shape resonance (LSR) appears and affects the transmission mechanism. The U shape hole array is used to investigate the transition between SP and LSR by changing total resonant length of U shape hole. 2nd LSR appears as the resonant length continuously increase. When resonant wavelength of 2st LSR is close to the SP , SP mode can be excited. The SP and LSR coexist in transmission spectra when the hole is enlarged. In second part of this thesis, the transmission spectra through samples with periodic H-shaped hole and more complicated hole which is a combination of multiple U shape are investigated. The observations indicate that the resonant length of localized shape resonance is the length of unfolded U-shaped part of the hole. LSR modes with smaller resonant U-shaped length don''t always appear. The transmission spectra reveal that the LSR mode with largest resonant U-shaped part of the hole could always be observed. In addition, LSR mode with non-U-shaped resonant path cannot be seen in our sample. In addition,The transmission spectra with different polarization reveal that LSR with different order and resonant path can be excited by different polarized light.