基于环偶极子共振的高Q值超材料传感器

High-Q Metamaterial Sensor Based on Toroidal Dipole Resonance

提出了一种结构简单且可激发环偶极子共振的全介质超材料,该超材料具有高品质因子(Q)和高灵敏(FOM)值。基于环偶极子共振电流密度和电场分布,分析了超材料能够激发环偶极子的内在物理机制。经模拟计算发现,全介质超材料的Q值和FOM值可分别达到14000以上和672.7/RIU左右。基于谐振子耦合模型和共振波长处的电场分布,分析了超材料全介质开口环间距和探测物厚度对其Q值和环偶极子共振波长的影响机理。该研究可以为设计制备应用于生物、化学探测的高质量环偶极子共振超材料传感器提供理论基础。

An alldielectric metamaterial with a simple structure and can excite toroidal dipole resonance,and that exhibits a high quality factor(Q)and high sensitivity(FOM)value is proposed.Based on the current density and electric field distribution of toroidal dipole resonance,the intrinsic physical mechanism that the metamaterial can excite the toroidal dipole is analyzed.Numerical simulation shows that the Q and FOM values of the alldielectric metamaterial can reach more than 14000 and approximately 672.7 nm/RIU,respectively.Based on the harmonic oscillator coupling model and the electric field distribution at the resonant wavelength,the influence mechanism of spacing between the rings and thickness of the detector on the Q value and the resonant wavelength is also analyzed.This study can provide a theoretical basis for the design and preparation of highquality toroidal dipole resonance metamaterial sensors for use in biological and chemical detection.