对入射角和极化不敏感的THz超材料传感器设计

doi:10.16553/j.cnki.issn1000-985x.2024.0183

摘要/Abstract

摘要： 常见的太赫兹波传感器均是在正入射条件下产生响应,进而区分待测物,如果激励的太赫兹波不是正入射,其区分的线性度将受到影响。本文设计了一种对称结构的齿轮状太赫兹超材料传感器,其整体结构由表面齿轮状金属图案与聚氨酯基底构成。该设计在0.2~1.2 THz上有较高的透射率,且当电磁波入射角在0°~70°发生变化时,传感器谐振点变化稳定,对入射角不敏感,弥补了目前传感器的缺陷,具有良好的抗入射角不确定性的能力。同时此传感单元对入射波的极化也不敏感,扩展了太赫兹传感器的应用范围。本文还推导了灵敏度S与待测物折射率之间的数学关系,用不同折射率的待测物模拟不同液体进行灵敏度检测,结果显示谐振频率变化与待测物折射率变化呈现良好的线性关系。传感器的灵敏度在-0.28~-0.13 THz/RIU,性能较为优越。

关键词: 超材料传感器, 灵敏度, 齿轮单元, 谐振频率, 太赫兹, 大角度入射

Abstract: Common terahertz wave sensors work under normal incidence conditions to distinguish the device under test (DUT). However, if the excited terahertz wave is not normal incident, its discrimination linearity will be affected. In this paper, a symmetrical gear-shaped terahertz metamaterial sensor is proposed. The structure of the sensor consists of a surface gear shaped metal pattern and a polyurethane substrate. This design has high transmittance in the range of 0.2~1.2 THz, and when the incident angle of electromagnetic waves changes within the range of 0°~70°, the resonance point of the sensor changes very stably and is insensitive to the incident angle, which compensates for the current shortcomings of sensors and has good ability to resist the uncertainty of the incident angle. At the same time, this sensing unit is also insensitive to the polarization of the incident wave, which expands the application range of terahertz sensors. The mathematical relationship between the sensitivity S and the refractive index of the object to be tested is derived. The sensitivity of the sensor is tested by the liquids with different refractive indices as the measurands. The result shows that there is a good linear relationship between the change of resonant frequency and the refractive index of sample. The sensitivity of the sensor is between -0.28 to -0.13 THz/RIU, demonstrating superior performance.

Key words: metamaterial sensor, sensitivity, gear unit, resonant frequency, terahertz, large of incidence

中图分类号:

TN713
TP212

李翔宇, 韩华, 王扬, 姚夏元. 对入射角和极化不敏感的THz超材料传感器设计[J]. 人工晶体学报, 2025, 54(1): 59-68.

LI Xiangyu, HAN Hua, WANG Yang, YAO Xiayuan. Design of THz Metamaterial Sensors Insensitive to Incidence Angle and Polarization[J]. Journal of Synthetic Crystals, 2025, 54(1): 59-68.

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