基于环偶极子超材料的太赫兹波段高灵敏度传感器设计

High sensitivity toroidal metamaterial sensor in THz range

本文利用一对镜像对称开口谐振环实现了太赫兹波段的环偶极子超材料设计。通过垂直入射电磁波激励,该亚波长结构在2.75 THz处产生高Q值透射谷。近场分析表明,谐振环中反向流动的电流可产生一对首尾相接的磁偶极子,从而实现涡旋状磁场的环偶极子。各多极子远场散射能量计算结果进一步证明迅速增强的环偶极子是产生该高Q值透射谷的主要因素。该环偶极子超材料可用于折射率传感器的设计,其灵敏度可达114 GHz/RIU,可用于探测周围环境微小参数的变化。该设计对基于环偶极子超材料的太赫兹波段生物和化学分子的高灵敏度传感器设计提供了新的思路。

Here a high sensitive sensor was realized with toroidal metamaterial in THz range.The proposed subwavelength structure was comprised of two mirror split ring resonators with counterpropagating currents to acquire vortex magnetic field.In the far-field scattered power of multipoles,it can be observed that the high Q-factor transmission dip at 2.75 THz is due to the sharply enhanced toroidal dipole.The sensitivity of the proposed refractive index sensor can reach up to 114 GHz/RIU.The toroidal sensor can be used to detect minor changes in the surrounding environments and have potential applications in high sensitivity biosensor and chemosensor at THz range.