Modulation of the resonance frequency in double-split ring terahertz metamaterials

We investigated the resonant transmission of planar metamaterials structured in symmetric and asymmetric double-split rings through simulations and experiments. With increasing of the arm lengths the transmission dips coming from the LC resonance red-shift by 50-100 GHz. In addition to the LC resonance, dipole resonance occurs in the asymmetric structure which is formed by displacing the two splits away from the center in the same direction. Sensing characteristics by changes in the media surrounding the structures were demonstrated by simulations and experiments. By changing the surrounding medium from air to oil, we obtained resonant frequency red-shifts of 30-80 GHz. This study may lead to the application of these terahertz devices as modulators and sensors.