Tunable terahertz fishnet metamaterials based on thin nematic liquid crystal layers for fast switching

• Published in: Scientific reports Vol. 5; no. 1; p. 13137
• Main Authors: Zografopoulos, Dimitrios C., Beccherelli, Romeo
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14.08.2015; Nature Publishing Group
• Subjects: 639/166/987; 639/766/1130/2799; Anisotropy; Humanities and Social Sciences; Investigations; multidisciplinary; Science; Voltage
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep13137

The electrically tunable properties of liquid-crystal fishnet metamaterials are theoretically investigated in the terahertz spectrum. A nematic liquid crystal layer is introduced between two fishnet metallic structures, forming a voltage-controlled metamaterial cavity. Tuning of the nematic molecular orientation is shown to shift the magnetic resonance frequency of the metamaterial and its overall electromagnetic response. A shift higher than 150 GHz is predicted for common dielectric and liquid crystalline materials used in terahertz technology and for low applied voltage values. Owing to the few micron-thick liquid crystal cell, the response speed of the tunable metamaterial is calculated as orders of magnitude faster than in demonstrated liquid-crystal based non-resonant terahertz components. Such tunable metamaterial elements are proposed for the advanced control of electromagnetic wave propagation in terahertz applications.