基于双开口环型的太赫兹超材料传感器设计

Design of Terahertz Metamaterial Sensor Based on Double Opening Square Ring

设计了一款可用于检测材料折射率及厚度的双开口环型太赫兹超材料传感器,其结构由双开口方环与圆环嵌套的超材料结构和聚酰亚胺衬底两部分构成。当太赫兹波垂直入射超材料表面时,该传感器结构在0.8~1.8 THz范围内形成三个高Q值谐振峰(中心频率分别为f_(1),f_(2)和f_(3))。通过探讨超材料结构表面电流分布与三个谐振峰形成的关系,观察到超材料结构对入射太赫兹波的不同响应特性导致产生不同的表面电流分布。此外,还对该传感器在折射率传感和厚度传感方面的应用进行了探究。在待测物厚度一定的情况下,该传感器在谐振频率f_(1),f_(2)和f_(3)处的传感灵敏度分别可达170,103和119 GHz/RIU,均具有优越的传感特性,可利用其多谐振峰进行高灵敏度折射率传感。这种高灵敏度的多谐振峰折射率传感器可以检测到待测分析物的微小变化,在生物化学检测领域具有广阔的应用前景。

A terahertz metamaterial sensor based on double opening ring is proposed, which can be used to detect the refractive index and thickness of materials. The structure of the sensor consists of two parts: a metamaterial structure with two open square rings and a ring nested inside, and a polyimide substrate. When the terahertz wave is perpendicular to the surface of the metamaterial, three high-Q resonance peaks are formed in the range of 0.8~1.8 THz. By discussing the relationship between the surface current distribution and the formation of three resonance peaks, it is observed that the different response characteristics of the metamaterial structure to the incident terahertz wave lead to different surface current distribution. In addition, the applications of the sensor in refractive index sensing and thickness sensing are also explored. The sensing sensitivities of 170, 103 and 119 GHz/RIU can be realized for the resonant frequencies f_(1),f_(2) and f_(3), respectively, at a given thickness, all of which have superior sensing characteristics and can be used for high-sensitivity refractive index sensing with their multiple resonant peaks. This highly sensitive refractive index sensor can detect small changes in the analyte to be measured and has promising applications in the field of biochemical detection.