可实现90度偏振转换的超表面研究毕业论文
2020-07-14 22:09:53
摘 要
ABSTRACT 2
第一章 绪论 3
1.1 简述超表面的原理及其研究概况 3
1.2 本论文的研究内容 6
第二章 基于CST软件的模型设计 7
第三章 偏振偏转器的透射谱 19
第四章 电场、磁场、电流密度及能流密度 26
第五章 结论 30
参 考 文 献 31
摘 要
超表面(metasurfaces,又称特异介质表面)的概念源于超材料(metamaterials,又称特异材料或超构材料)。可以说超表面就是平面版的超材料。超材料的概念是由人工制成的亚波长电磁微型结构单元按照一定的宏观顺序排列而成的人工材料。对于特征结构尺寸小于一个波长的超薄的超材料称之为超表面。由于超表面有厚度超薄和性能可控的优势,与传统光学器件相比,用超表面制成的光学器件的空间尺寸缩小地很多,这正是芯片级光学器件所急需的。透过其他前人的文献资料,总结了超表面技术的发展状况和本课题的研究背景,对未来超表面技术的发展趋势提出来设想。本论文基于人工超材料技术,针对近红外光谱设计了三层矩形孔阵列结构的偏振旋转器件。运用软件(CST MICROWAVE STUDIO)微波仿真软件,理论性地探讨和验证了该结构实现偏振转换的可靠性并且得到了一些有效参数及图样,运用这些数据对以往的三层矩形孔阵列结构做出了一些有效的改进。针对矩形孔阵列结构的偏振转换,改变超表面的平面几何特征尺寸,厚度,间距等可控参数,分析了矩形孔阵列结构大小对偏振光透射转换效率的影响。在一定范围内,增大了中间矩阵孔占单胞截面的大小,提高了透射效率,使得工作带宽上的透射效率稳定且高效。对于一些几何参数的改进后文会具体说明。总之,研究结果在提高三层矩形孔阵列结构的90度的偏振旋转器件的透射率方面有重要的理论研究价值。
关键词:90度偏振转换;超表面;三层矩形孔阵列结构。
ABSTRACT
The concept of metasurfaces originates from metamaterials. Metamaterial refers to an artificial composite material made up of artificial sub-wavelength electromagnetic microstructure units arranged in a certain macroscopic order. Ultra-thin metamaterials with feature sizes smaller than one wavelength are called super surfaces. Due to the advantages of ultra-thin surfaces and controllable performance, the space size of super-surface-based optical devices is greatly compressed compared to conventional optical devices, leading to the development of chip-level optical devices. Through the literature of other predecessors, the development status of the super-surface technology and the research background of the subject were summarized, and the future development trend of the super-surface technology was proposed. In this dissertation, based on the artificial metamaterial technology, a polarization rotating device with three-layer rectangular aperture array structure was designed for near-infrared spectroscopy. Using CST MICROWAVE STUDIO microwave simulation software, theoretically discussed and verified the structure to achieve the reliability of polarization conversion and obtained some effective parameters and patterns, using these data to make some effective three-tier rectangular hole array structure Improve. For the polarization conversion of the rectangular array structure, the controllable parameters such as the geometrical feature size, thickness, and pitch of the super surface are changed, and the transmission conversion efficiency of the polarized light of the rectangular aperture array structure is analyzed. Within a certain range, the size of the cell cross-section occupied by the intermediate matrix is increased, the transmission efficiency is improved, and the transmission efficiency over the working bandwidth is stable and highly efficient. The improvement of some geometric parameters will be explained in detail later. In conclusion, the research results have important theoretical research value in improving the transmittance of 90 degree polarization rotating devices with three-layer rectangular array structure.
Key Words: 90 degree polarization conversion; metasurfaces; three-layer rectangular hole array structure
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