Research on a Novel Terahertz Metasurface Sensor Based on Toroidal-Coupled Anapole Mode

文章设计了一种基于Toroidal和Anapole模式耦合的太赫兹超表面传感器，通过优化金属谐振器结构，实现了高效电磁场局域化和高灵敏度检测。该传感器由对称开口环和金属条带组成，在高阻硅衬底上激发双谐振模式。仿真分析表明，在0.73 THz和0.89 THz处分别观察到显著的Toroidal和Anapole模式共振，其中环偶极矩与电偶极矩的相位调控是关键物理机制。通过折射率灵敏度测试，两种模式分别达到260 GHz/RIU和250 GHz/RIU的灵敏度，且频移响应高度同步，展现了其在多模式协同传感中的应用潜力。研究结果为太赫兹波段的高性能超表面传感器设计提供了新思路，尤其在物质检测领域具有重要价值。This study presents a terahertz metasurface sensor based on the coupling of Toroidal and Anapole modes, achieving highly localized electromagnetic fields and high-sensitivity detection through optimized metal resonator structures. The sensor consists of symmetrically arranged split rings and metal strips fabricated on a high-resistivity silicon substrate, enabling dual-mode resonance. Simulation results reveal distinct Toroidal and Anapole mode resonances at 0.73 THz and 0.89 THz, respectively, with the phase modulation between toroidal and electric dipole moments serving as the key physical mechanism. Refractive index sensitivity tests demonstrate values of 260 GHz/RIU and 250 GHz/RIU for the two modes, with highly synchronized frequency shifts, highlighting their potential for multi-mode cooperative sensing. This work provides a novel approach for designing high-performance terahertz metasurface sensors, particularly for applications in material detection.