Mechanical control of terahertz plasmon-induced transparency in single/double-layer stretchable metamaterial

Abstract

Active control of metamaterial properties in stretchable devices is crucial for advanced terahertz (THz) applications, involving large mechanical deformation or stretching. Single/double-layer mechanically tunable THz metamaterial devices based on the polymer polydimethylsiloxane are proposed and experimentally studied herein. The plasmon-induced transparency (PIT) effect is observed in the transmittance spectrum of the single-layer metamaterial, originating from the near-field coupling of two bright modes. Similarly, a bright-dark-coupled PIT system is obtained in the double-layer metamaterial. Furthermore, an external mechanical stretching could exert a switch effect on the sample. The PIT resonances of the single/double-layer metamaterials disappear when the stretching ratio is further increased, as the increased distance between the resonators blocks the coupling effect. The proposed design enriches the approaches to the modulation of the sensitive PIT effect and broadens the applications of stretchable THz equipment.