提出了一种基于双复合结构层(CSLs)的宽带太赫兹超材料吸收体,其中复合结构层I由4个不同的圆环金属结构组成,复合结构层II由4个不同的方形金属结构组成。采用时域有限差分法详细研究和讨论了吸收体的吸收谱线、磁场能量分布、表面电流分布,以及偏振角度和入射角度对吸收的影响。结果表明:该吸收体能够有效抑制高阶共振峰,特别是当太赫兹波正入射时,吸收率大于90%的吸收带宽可达0.722 THz,中心频率为2.041 THz。

A broadband terahertz metamaterial absorber is proposed based on the double composite structure layers (CSLs). The composite structure layer I and composite structure layer II comprise four different-sized gold rings and square plates, respectively. Further, the finite difference time domain (FDTD) method is employed to theoretically investigate and discuss the effects of absorption spectrum, magnetic field distribution, surface current distribution, polarization angle, and incident angle on absorption. The results show that the high-order resonance peaks can be effectively suppressed by this absorber. Furthermore, in case of normal incidence, the absorption bandwidth corresponding to absorptivity greater than 90% is 0.722 THz, and its central frequency is approximately 2.041 THz.