A Tunable Polarization-Dependent Terahertz Metamaterial Absorber Based on Liquid Crystal

作者:Deng, Guangsheng; Lu, Yujiao; Yin, Zhiping; Lai, Weien; Lu, Hongbo; Yang, Jun*; Yang, Aifeng; Ye, Yang; Liu, Dayong; Chi, Baihong
来源:Electronics, 2018, 7(3): 27.
DOI:10.3390/electronics7030027

摘要

In this paper, a tunable polarization-dependent terahertz (THz) metamaterial absorber based on liquid crystal (LC) is presented. The measurement results show that absorption peak is at 239.5 GHz for a TE-polarized wave and 306.6 GHz for a TM-polarized wave, without exerting the bias voltage on the LC layer. An increase in bias voltage affects the orientation of LC molecules and causes redshifted resonant frequencies. By adjusting the bias voltage from 0 to 10 V, frequency tunabilities of 4.7% and 4.1% for TE- and TM-polarized waves, respectively, were experimentally demonstrated. Surface current and power loss distribution was analyzed to explain the physical mechanism of the absorber, while the absorption dependence on geometrical parameters and incident angles was also studied in detail. According to the obtained results, the proposed absorber is shown here to be capable of achieving tunable polarization-dependent absorption, and to have potential application in terahertz polarization imaging, terahertz sensing, and polarization multiplexing.