A Tunable Polarization-Dependent Terahertz Metamaterial Absorber Based on Liquid Crystal
A Tunable Polarization-Dependent Terahertz Metamaterial Absorber Based on Liquid Crystal
复制标题
基于液晶的可调谐偏振相关太赫兹超材料吸收器
DOI：
10.3390/electronics7030027
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发表时间：
2018-03-01
期刊：
影响因子：
2.9
通讯作者：
Chi, Baihong
中科院分区：
文献类型：
--
作者：
Deng, Guangsheng;Lu, Yujiao;Chi, Baihong
提出了一种基于液晶的可调谐偏振相关太赫兹（THz）超材料吸收体。测量结果表明，在不施加偏压的情况下，薄膜的TE极化吸收峰位于239.5GHz，TM极化吸收峰位于306.6GHz。偏置电压的增加会影响LC分子的取向，并导致谐振频率红移。通过将偏置电压从0调整到10 V，实验证明TE和TM极化波的频率可调谐性分别为4.7%和4.1%。分析了表面电流和功率损耗的分布，解释了吸收体的物理机制，并详细研究了吸收体的几何参数和入射角对吸收的影响。根据所得到的结果，这里所提出的吸收体是能够实现可调谐的偏振相关的吸收，并在太赫兹偏振成像，太赫兹传感，偏振复用有潜在的应用。
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.