Zang XiaoFei, Shi Cheng, Chen Lin, Cai Bin, Zhu YiMing, Zhuang SongLin
Shanghai Key Lab of Modern Optical System and Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, No. 516 JunGong Road, Shanghai 200093, People's Republic of China.
Sci Rep. 2015 Mar 10;5:8901. doi: 10.1038/srep08901.
Metamaterials, artificial electromagnetic media consisting of periodical subwavelength metal-based micro-structures, were widely suggested for the absorption of terahertz (THz) waves. However, they have been suffered from the absorption of THz waves just in the single-frequency owing to its resonance features. Here, in this paper, we propose a simple periodical structure, composed of two 90 degree crossed dumbbell-shaped doped-silicon grating arrays, to demonstrate broadband THz wave absorption. Our theoretical and experimental results illustrate that THz waves can be efficiently absorbed more than 95% ranging from 0.92 THz to 2.4 THz. Such an ultra-wideband polarization-independent THz absorber is realized mainly based on the mechanisms of the anti-reflection effect together with the [±1, 0]-order and [0, ±1]-order grating diffractions. The application of our investigation can be extend to THz couplers, filters, imaging, and so on.
超材料是由周期性亚波长金属基微结构组成的人工电磁介质，被广泛认为可用于太赫兹（THz）波吸收。然而，由于其共振特性，它们仅在单频下吸收太赫兹波。在此，我们提出一种简单的周期性结构，由两个呈90度交叉的哑铃形掺杂硅光栅阵列组成，以实现宽带太赫兹波吸收。我们的理论和实验结果表明，太赫兹波在0.92太赫兹至2.4太赫兹范围内可被有效吸收，吸收率超过95%。这种超宽带偏振无关太赫兹吸收器主要基于抗反射效应以及[±1, 0]阶和[0, ±1]阶光栅衍射机制实现。我们的研究成果可应用于太赫兹耦合器、滤波器、成像等领域。
