Terahertz characterization of tunable metamaterial based on electrically controlled nematic liquid crystal

The terahertz time domain spectroscopy (THz-TDS) system is used to determine the effects of an AC bias voltage on the tunable response of a metamaterial transducer. The tunability of the metamaterial structure, which is based on the rod-split-square resonator, is demonstrated at terahertz frequencies through electrical control of the nematic liquid crystal orientation. Experimental results show that the metamaterial device can be tuned effectively (with transmittance change of up to 19%) by changing the magnitude of the AC bias voltage from 0 to 300 V. This type of tunable metamaterial could find application in the development of devices operating in the THz frequency region for filtering, modulating, and switching of the electromagnetic signals. (C) 2014 AIP Publishing LLC.