基于双十字结构的太赫兹传感器设计

Design of Terahertz Sensor Based on Double Cross Structure

摘要:

设计了一种基于双十字结构的多谐振峰太赫兹超材料传感器。整体结构由表面金属图案、中间介质和底面金属板组成。基本单元的表面图案呈双十字交叉状,介质材料为聚酰亚胺(Polyimide)。仿真结果表明,所提出的结构具有5个不同的谐振吸收峰,吸收率均超过90%。前3个谐振峰分别对应单元结构内部不同区域形成的基本磁谐振,后2个谐振峰则来源于单元结构间的相互作用。当传感器表面覆盖15 μm厚度分析物时,该传感器各个谐振峰的灵敏度分别为72、137、234、353和252 GHz/RIU,且谐振峰偏移量与待测分析物折射率变化量呈较强的线性关系,具有优越的传感特性。此外,多峰传感器稳定性优于传统的单峰或双峰传感器,具有良好的抗干扰能力,有助于降低测量误差。本文所提出的这种高灵敏度多谐振峰传感器在微量分子检测领域具有广阔的应用前景。

Abstract:

A multiple resonance peaks terahertz metamaterial sensor based on double-cross structure is designed. The overall structure is composed of surface metal pattern, intermediate medium and bottom metal plate. The surface pattern of the basic unit is double-cross and the medium material is polyimide. The simulation results show that the proposed structure has five different resonant absorption peaks, and the absorption rate is more than 90%. The first three resonance peaks correspond to the basic magnetic resonance formed in different regions of the unit structure, and the last two resonance peaks are derived from the interaction between the unit structures. When the surface of the sensor is covered with an analyte with a thickness of 15 μm, the sensitivity of each resonance peak of the sensor is 72, 137, 234, 353 and 252 GHz/RIU, respectively, and the resonance peak offset has a strong linear relationship with the refractive index change of the analyte to be measured, which has superior sensing characteristics. In addition, the stability of the multiple peaks sensor is better than that of the traditional single peak or double peak sensor, and it has good anti-interference ability, which helps to reduce the measurement error. The proposed high sensitivity multiple resonance peaks sensor has a broad application prospect in the field of trace molecule detection.