【摘要】 近年来,金属亚波长结构由于在负折射材料方面存在巨大应用价值,及可作为太赫兹波段的光学限制器等器件应用,引起了研究者们的广泛关注。本文采用电子束曝光离子束刻蚀的方法在金膜上制备了亚波长的超大长宽比U型开口矩形谐振器阵列结构,利用时域有限差分方法(FDTD)和太赫兹时域光谱技术(THz-TDS)对U型阵列结构的太赫兹波透射光谱响应进行了测量和分析,讨论了透过率对结构几何参数的依赖特性和异常透射的物理机制。通过这种U型开口谐振器能够实现太赫兹波的强局域和场增强,可将太赫兹波局域在波长千分之一的尺寸上,从而实现了太赫兹的异常透射现象,这种超大长宽比的U型开口谐振器可在太赫兹探测、太赫兹成像及其他光学器件的设计上得以应用。更多还原

【Abstract】 Metal sub-wavelength periodic array structures have attracted great interest due to their potential applications in the construction of meta-material, and the investigation of the metal sub-wavelength periodic array structures is essential for the development of optoelectronic devices, such as optical filters, ultrafast optical switches and optical limiters etc., operating in the microwave and THz spectral region. In this thesis, we investigated numerically and experimentally the transmission properties of the metal sub-wavelength periodic array structures in the THz spectral region based on the finite-difference time-domain method and the terahertz time domain spectroscopy technique. The U-shaped open resonators with huge aspect ratio were designed. We employed the electron beam exposure and ion beam lithography technology to construct the samples and measured its transmission spectrum. At the same time, we explored the dependence of the transmission on the structure parameters and tried to find out the physical mechanism for the abnormal transmission. After a series of studies, it was found that the localization of THz wave and electric field enhancement could be achieved by the U-shaped open resonator. The incident THz wave could be localized in a region whose dimension is only one-thousand of the central wavelength of the THz wave. We believe that the U-shaped open resonators with huge aspect ratio could be applied in the fabrication of sensors and other optical devices in the future.更多还原