| Summary: | 碩士 === 國立交通大學 === 光電工程系所 === 93 === Metal plates perforated with two-dimensional periodic arrays of sub-wavelength holes (2D-MHAs) exhibit high transmission at selective terahertz frequencies. This mechanism of the enhanced transmission characteristic is usually attributed to the resonant coupling between the incident light and surface plasmon-polaritons (SPPs) which are located at the metal-dielectric surfaces. We experimentally and numerically investigate the role of material in the holes on transmission characteristics of the 2D-MHA. New phenomena, however, appear when holes of the 2D-MHA are filled with dielectric material. We find distinctive THz transmission characteristics depending on the thickness and properties of the adjacent medium for the 2D-MHA of which holes are filled with UV-gel. For deeper holes, SPP can exhibit two distinct modes, coupled and uncoupled types as confirmed in the simulated results for the electric field using finite-difference time-domain (FDTD) algorithm.
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