Polarization-sensitive terahertz resonator using asymmetrical F-shaped metamaterial

A design of tunable terahertz (THz) resonator by using asymmetrical F-shaped metamaterial (AFSM) is presented, which is composed of Au layer fabricated on silicon-on-insulator (SOI) substrate. There are three designs of AFSM with different length of F-shaped microstructure, which are 60 gm, 65 mu m, and 70 mu m kept other parameters as constant. The electromagnetic response of tunable THz resonator exhibits the switch function for single-band resonance at transverse magnetic (TM) mode and dual-band resonance at transverse electric (TE) mode by changing the gap between AFSM microstructures. These characterizations of device can be used for a THz filter at TM mode and a THz switch at TE mode. To compare the proposed AFSM device with and without a gap, that can be switched in the range of 0.20-0.40 THz for single-band switching resonance at TM mode and dual-band switching resonance at TE mode, respectively. These resonances are ultra-narrow bandwidths with a highest Q-factor of 40 at TE mode and kept as stable at 20 at TM mode. Such results are very suitable to be used for an environmental sensor. To further enhance the flexibility of AFSM device, it is exposed on ambient environment with different refraction index for high-efficiency environmental sensor with a correlation coefficient of 0.9999. This study paves a way to the possibility of high-sensitivity of tunable THz metamaterial in filter, switch, polarizer, and other applications.