Tuning of Fano resonances in terahertz metamaterials

Abstract

To overcome the large linewidth in the transmission spectra of metamaterials which have been applied in fields such as bio-sensing and light modulating in terahertz regime, a set of terahertz metamaterials which are composed of two different split ring resonators are designed and fabricated to explore the characteristics such as Fano resonances and quality factors by changing the geometry structure. The results illustrate that the Fano resonance is tuned both in the depth and in the width when the gap position of the metamaterial with asymmetric structure varies. Meanwhile, to obtain extremely sharp Fano resonances, the gap width is reduced, which greatly improves the quality factor of the Fano line shape in the transmission spectra, presenting a narrow linewidth of merely 11 GHz in the simulation and 23 GHz in the experiment.