Wang Ben-Xin, He Yuanhao, Lou Pengcheng, Xing Wenhui
School of Science, Jiangnan University Wuxi 214122 China
Nanoscale Adv. 2020 Jan 3;2(2):763-769. doi: 10.1039/c9na00770a. eCollection 2020 Feb 18.
A dual-band terahertz metamaterial absorber composed of two identical square metallic patches and an insulating medium layer on top of a continuous metallic ground is demonstrated. Two resonance peaks (labeled A and B) with near 100% absorbance are obtained, of which peak A derived from the localized resonance of the two square patches has a line-width of 0.2571 THz and quality factor of 6.9156, while peak B which resulted from the hybrid coupling of the localized resonance of the two square patches and surface lattice resonance of the device has a very narrow line-width of 0.0083 THz and large quality factor of 296.2771. Narrow line-width and large quality factor have important prospects in sensing application. Based on this, the sensing performance of the device is explored; it is revealed that peak B exhibits highly sensitive sensing ability (including a sensing sensitivity of 1.9010 THz per RIU and figure of merit of 229.04) in terms of the surrounding index. In addition, the influence of structural parameters on the absorption performance is discussed to further verify the formation mechanism of these two absorption peaks.
展示了一种双频太赫兹超材料吸收器，它由两个相同的方形金属贴片和一个位于连续金属接地层顶部的绝缘介质层组成。获得了两个吸收率接近100%的共振峰（标记为A和B），其中源自两个方形贴片局部共振的峰A线宽为0.2571太赫兹，品质因数为6.9156，而由两个方形贴片的局部共振与器件表面晶格共振的混合耦合产生的峰B线宽非常窄，为0.0083太赫兹，品质因数很大，为296.2771。窄线宽和高品质因数在传感应用中具有重要前景。基于此，探索了该器件的传感性能；结果表明，就周围折射率而言，峰B表现出高度灵敏的传感能力（包括每RIU 1.9010太赫兹的传感灵敏度和229.04的品质因数）。此外，还讨论了结构参数对吸收性能的影响，以进一步验证这两个吸收峰的形成机制。
