基于双椭圆结构的高Q值太赫兹超材料传感器

High Q-Value Terahertz Metamaterial Sensor Based on Double Ellipse Structure

设计了一种基于双椭圆结构的高品质因数(Q值)太赫兹(THz)超材料传感器,该传感器的每个单元均包含两个厚度为0.2μm、位于聚合物基底上且互成一定角度的金属椭圆。用时域有限积分法对传感器的结构进行了优化,通过破坏面内反转对称性使金属椭圆阵列组成的超表面激发垂直入射的THz波。实验结果表明,该传感器的Q值高达348。在传感器表面覆盖厚度为20μm的待测物时,其灵敏度为293 GHz/RIU(Refractive index unit),可用于高灵敏度检测、痕量生物样本检测和疾病早期诊断等领域。

A high quality factor(Q-value) terahertz(THz) metamaterial sensor based on double ellipse structure is designed in this paper. Each cell of the sensor contains two 0.2 μm thick metal ellipses at a certain angle and located on the polymer substrate. The sensor structure is optimized by the finite integral time domain method, and the destruction of in-plane inversion symmetry leads to the excitation of vertically incident THz waves by the metasurface composed of the metal elliptical array. Experimental results show that the Q-value of the sensor is as high as 348. When the sensor surface is covered with a test object with a thickness of 20 μm, its sensitivity is 293 GHz/RIU(refractive index unit), and the sensor can be applied to high-sensitivity detection, trace biological sample detection, and early disease diagnosis.