摘要
自然界中很多材料在太赫兹(THz)频段没有电磁响应,THz超材料的出现为太赫兹技术的发展和应用带来了新的机遇.但目前超材料太赫兹响应的调节方式比较繁琐,影响了理论与应用研究的开展.作者提出一种调制太赫兹超材料响应的简易新方法,即将超材料的结构单元整体按比例地放大和缩小.仿真结果表明,已满足阻抗匹配条件的超材料结构经整体比例变化之后,仍然满足阻抗匹配条件;而且,调整后超材料的吸收频率与尺寸变化的倍数成反比;令人惊奇的是,超材料的响应频带也随着单元尺寸的整体缩小而变宽.通过这种简易的尺寸变化方式,我们可以利用普通的超材料结构,得到一定范围内对任意入射频率具有完美吸收(吸收峰值大于98%)的太赫兹超材料.这种调制方式使超材料的设计变得更加简化,为超材料的理论与应用(特别是在器件中的应用)研究提供了更广阔的空间.
M ost materials in nature do not have electromagnetic response in the terahertz（ THz） frequency range. THz metamaterials that were invented recently provide an opportunity for the development and application of THz technology.However,the conventional methods for modulating the THz metamaterials are complicated. In this paper,we present a novel and simple way to adjust the THz metamaterials just by zooming in and out the THz metamaterial＇s unit. Simulation results showthat THz metamaterials are still impedance-matching,even after the ratio change. In addition,the resonance frequency changes inversely with the unit ratio. Absorption bandwidth will be widened when the THz metamaterial＇s unit is shrunk. According to our approach,any response frequency of THz metamaterials（ a value of absorption peak is greater than 98%） can be acquired within specific frequency bands. This modulation simplifies the THz metamaterial design and broadens the applications of metamaterials in detectors.
出处
《红外与毫米波学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第1期44-50,共7页
Journal of Infrared and Millimeter Waves
基金
国家自然科学基金(NSFC 61071032,61377063)~~
关键词
超材料
太赫兹
吸收频率
响应频带
调控
metamaterials
Terahertz
response frequency
absorption bandwidth
modulation
