针对传统超材料的太赫兹响应调控难度大、程序复杂的缺点, 提出调节超材料太赫兹响应特性的一种新方法.该方法是在传统三层超材料的结构与材料参数均不变的情况下, 在中间介质层中引入一条附加的金属条, 仅通过调节该金属条的位置和线宽, 就能实现超材料对入射太赫兹波的响应频率、吸收峰值等的有效调节.结果显示, 当附加金属条由底层向表层的方向移动时, 超材料的响应频率红移.当金属条位于介质的中间位置时, 超材料的吸收率达到最大(99.98%).而且, 当金属条的线宽增大时, 超材料的响应频率红移、吸收增强.此外, 当太赫兹入射角≤45°时, 该超材料的中心响应频率稳定、吸收率峰值较高.但是, 当入射角＞45°时, 超材料的响应频率蓝移、吸收率峰值明显下降.根据这种新方法, 能够对超材料的太赫兹响应进行有效控制, 同时避免设计超材料结构的复杂过程.

Considering the difficulty and complexity in adjusting the terahertz (THz) response of the traditional metamaterials (MMs), we proposed a novel method to adjust the THz response characteristics of MMs. Our MMs possess the same structural and material parameters as those of the traditional three-layer MMs, but differently, an additional metal strip is introduced in the middle dielectric layer. Through changing the position and line width of the additional metal strip, the response frequency and absorption for incident THz wave can be effectively adjusted. Results show that if the additional metal strip moves from near the bottom metal to the surface metal, the response frequency is red shifted. If the additional metal strip is located in the middle of the dielectric layer, the absorption reaches maximum (99.98%). If the width of the additional metal strip is enlarged, the response frequency is red shifted, and the absorption is increased. In addition, if the incident angle is ≤45o, both the central response frequencies of the traditional and novel MMs remain stable, and their absorptions are high. However, if the incident angle is >45o, their central response frequencies blue shift, and their absorptions decrease significantly. According to this novel method, the THz responses of MMs can be effectively adjusted, and the complex process for designing the MM structure can also be thus avoided.