双波段且偏振无关的超材料太赫兹窄带吸收器。

Dual-band and polarization-independent metamaterial terahertz narrowband absorber.

作者信息

Pan Wu, Shen Tao, Ma Yong, Zhang Zhen, Yang Huan, Wang Xi, Zhang Xuewen, Li Yi, Yang Lihao

出版信息

Appl Opt. 2021 Mar 10;60(8):2235-2241. doi: 10.1364/AO.415461.

Abstract

A dual-band terahertz metamaterial narrowband absorber is investigated based on a single simple windmill-shaped structure. The proposed metamaterial absorber achieves near-perfect absorption at 0.371 THz and 0.464 THz. The full width at half-maximum is 0.76% and 0.31% relative to absorption frequency. The multireflection interference theory is used for analyzing the absorption mechanism at low absorption frequency. The theoretical predictions of the decoupled model have excellent agreement with simulation results. By investigating the absorber's distribution of electric field and surface current density at high absorption frequency, the absorber's near-perfect absorption at the high absorption frequency originating from the magnetic resonance formed between the top metal structure and the bottom metal plane is explained. Besides, the absorber proposed is independent of the polarization angle. It is significant to various applications such as narrowband thermal radiation, photoelectric detection, biological sensing, and other fields.

摘要

基于单一简单风车形状结构，对一种双频太赫兹超材料窄带吸收器进行了研究。所提出的超材料吸收器在0.371太赫兹和0.464太赫兹处实现了近乎完美的吸收。半高宽相对于吸收频率分别为0.76%和0.31%。利用多反射干涉理论分析了低吸收频率下的吸收机制。解耦模型的理论预测与模拟结果具有很好的一致性。通过研究吸收器在高吸收频率下的电场和表面电流密度分布，解释了吸收器在高吸收频率下近乎完美的吸收源于顶部金属结构与底部金属平面之间形成的磁共振。此外，所提出的吸收器与偏振角无关。这对窄带热辐射、光电探测、生物传感等各种应用具有重要意义。