Hybrid semiconductor-dielectric metamaterial modulation for switchable bi-directional THz absorbers

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• 作者：Ly Nguyen Le^a ; Nguyen Manh Thang^a ; Le Minh Thuy^b ; Nguyen Thanh Tung^c ; ^{tungnt@ims.vast.ac.vn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Metamaterial absorbers ; Cut-wire pairs ; Tunable metamaterials
• 刊名：Optics Communications
• 出版年：2017
• 出版时间：15 January 2017
• 年：2017
• 卷：383
• 期：Complete
• 页码：244-249
• 全文大小：903 K

文摘

There is an increasing interest for electromagnetic metamaterials that show mutable absorption properties with real-time and dynamic control. In this paper, we investigate a modulation of bi-directional metamaterial absorbers that is thermally switchable at terahertz frequencies. The metamaterial absorber is composed of symmetric hybrid semiconductor-dielectric cut-wire-pair structures, whose electromagnetic responses can be actively manipulated by utilizing an external heat source. As increasing the temperature of metamaterials from 300 to 350 K, we demonstrate that the magnetic resonance can be systematically blue-shifted and overlapped with the electric resonance, which is unaffectedly settled at about 0.8 THz. This superposition provides an effective mechanism to control the absorption intensity from 43% to nearly 95%. Finite integration simulation technique, standard retrieval method, and equivalent circuit model are employed to elaborate our idea.