Periodic Metal Array Structure Of The Thz Transmission Spectra Features

In this thesis, the terahertz transmission characteristic of metallic periodic hole arrays are investigated by means of the terahertz time-domain spectroscopy (THz-TDS). The factors affected THz transmission properties are analyzed one by one. The main work of this thesis is focused on the relationship between the THz transmission properties and the hole shape, the array alignment, the period, the hole diameter of the periodic array of sub-wavelength holes. In order to understand the influence of these factors to the terahertz transmission properties, and to further understand the physical mechanism of the enhanced transmission in terahertz range. The main work in this thesis include as follows:Then we fabricated the periodic arrays of rectangular holes with different alignment in the copper foil. The influence of the array alignment to their terahertz transmission properties is studied. Finally, we fabricated the periodic arrays with the different aperture diameters and the different periods of apertures of the Au film on silicon substrate. The influence of the diameter and the period of apertures to their terahertz transmission properties are studied in detail.(1) The enhanced transmission phenomenon of the periodic arrays of holes is investigated in the terahertz range. The frequency selective properties of THz transmission of the metallic periodic array of holes are confirmed.(2) We fabricated the periodic arrays of rectangular holes and studied their THz transmission properties. These holes in the copper foils have the same areas but the different shape, the influence of the shape of holes to their terahertz transmission properties is studied. The shapes of holes strongly affect the amplitude and frequency position of the resonance transmission peak. Keeping the polarization angle of THz field and the incidence angle fixed, the positions of transmission peak shift towards lower frequencies and the maximum of transmission will be increased with the length-to-width ratio of the rectangular holes. (3) The polarization dependence of THz transmission of the periodic array of rectangular holes is studied. For the symmetrical samples, THz transmission characteristic of these samples independence of the polarization of incidence THz wave. For the nonsymmetrical samples, THz transmission characteristic of these samples depend on the polarization of incidence THz wave.(4) THz transmissions of the pattern array of rectangular holes are studied.(5) THz transmissions of metallic aperture array on the silicon substrate are studied. The dependence of THz transmission on the hole size and array period are investigated in detail. At the same time, we investigate the physical mechanism of the enhanced THz transmission by means of The Finite-Difference Time-Domain (FDTD) Method. The calculated results are compared with the experimental one.In summary, the mechanism of the enhanced THz transmission of the metallic periodic array of holes is studied from several aspects of the hole shape, the hole size, the alignment of holes, and the period of array. This work will provide a significant reference for investigating the photonic devices in the terahertz frequency range.