Dark mode tailored electromagnetically induced transparency in terahertz metamaterials

In this paper, a novel terahertz metamaterial structure composed of a pair of sub-wavelength reverse U-shaped split ring resonators (RUSRs) and cut wire (CW) resonator is designed to realize electromagnetically induced transparency (EIT) effect in weak coupling region. Theoretical and simulated results show that by modulating the relative coupling distance between CW and SRR or mutual distance between SRR pair, the EIT-like phenomenon can be tailored. Furthermore, by introducing photosensitive silicon (Si) cell into the units of the dark mode resonator, actively optical control of the EIT-like effect is realized through increasing the dark mode damping rate. The present work provides an alternative method to design ultrasensitive sensors, filters and slow-light devices in the THz regime.