A Multi-functional terahertz metamaterial with polarization-controlled EIT and broadband absorption

Abstract

A multi-functional terahertz metamaterial with electromagnetically induced transparency (EIT) and broadband absorptions is proposed. The unit cell of the metamaterial is comprised of an E shape and a split-ring resonator on the top of the polyimide. For TE and TM polarization, the temporal coupled-mode theory reveals that the EIT effect arises from coupling two resonators. The transparent windows are experimentally demonstrated at 0.205 THz and 0.44 THz for the TM and TE polarization, respectively. When the vanadium dioxide ([Formula: see text] film is added to the bottom of the polyimide and works in the metallic state, the metamaterial could absorb electromagnetic waves in the broadband for the two polarizations, even in the case of oblique incidence. For the TE polarization, the relative bandwidth of the absorption over 60 % absorptance is 119.8 % in the range of 0.307 THz–1.225 THz. Meanwhile, for the TM polarization, the bandwidth over 60 % absorption is 68.8 % within the range of 0.52 THz–1.065 THz. The proposed multi-functional terahertz metamaterial can be widely used in sensing technology, optical storage, stealth technology, and other fields in reality.