Actively tunable terahertz metamaterial with single-band and dual-band switching characteristic

We present a design of tunable terahertz (THz) metamaterial (TTM) with single-band and dual-band filtering and switching characteristics. The proposed device is composed of face-to-face split-ring resonator (SRR) and a central bar. By moving the SRRs to change the gap between SRRs and central bar, the free spectrum ranges (FSR) could be bi-directionally broadened 0.14 THz and narrowed 0.19 THz at TE and TM modes, respectively. To control the coplanar moving central bar, the electromagnetic response of TTM device exhibits polarization-dependent characteristic. TTM shows the switching characteristic between single-band to dual-band resonance at TE mode and exhibits resonance-insensitive to the displacement of central bar at TM mode. These results open an avenue to be potentially used for detector, sensor, and switch in the THz-wave applications.