基于超材料结构的高Q太赫兹滤波器

在半导体微纳工艺基础上研究了基于镜像非对称结构超材料太赫兹(THz)滤波器的性能。通过时域有限差分理论，模拟分析了滤波器工作频率下太赫兹电场强度和电流密度在微结构的分布，并阐述了微结构太赫兹波电磁共振的机理。基于太赫兹滤波器电磁损耗机制和微纳加工工艺条件，设计并优化器件开口环结构，使相邻开口环中产生电磁场的干涉相消，减少太赫兹辐射损耗，提高品质因子Q值。采用太赫兹时域光谱(THz-TDS)系统测试了滤波器的太赫兹透射特性，实验结果表明，在工作频率0.923 THz下，镜像非对称结构的平面太赫兹滤波器品质因子达到12.5。同时，研究了太赫兹电场方向对滤波器性能的影响。高Q太赫兹滤波器的研制为制备高速太赫兹电调制器等太赫兹器件提供了重要的实验依据。

Metamaterial structure based high quality terahertz filter

Terahertz(THz) filters with mirrored asymmetric metamaterial structure have been studied based on the micro-nanofabrication technology. According to the finite difference time domain theory, the electric field and current density distribution of the microstructure are simulated and analyzed. The mechanisms of THz electromagnetic resonance of THz filter and physical mechanism of THz radiation loss are also described. The asymmetric split ring of micro-structures is designed and optimized in order to reduce the radiation loss and improve the Q value of the quality factor. The performance of the THz filter is characterized in the THz Time Domain Spectroscopic(THz-TDS) system. It is found that the quality factor of the filters with mirrored asymmetric metamaterial reaches up to 12.5 at the frequency of 0.923 THz. At the same time, the dependence of the direction of THz electric-field E on the performance of THz filter is studied as well. The study of the THz filter provides an important experimental basis for the development of THz devices, such as electrically tunable THz modulator.