Liang Jiran, Zhang Ke, Lei Dangyuan, Yu Lize, Wang Shuangli
Appl Opt. 2021 Apr 10;60(11):3062-3070. doi: 10.1364/AO.417054.
Terahertz absorbers combined with phase-changing are a class of stealth materials with adjustable absorptance. However, such absorbers still suffer from insufficient absorption bandwidth. We propose a three-layer terahertz (THz) absorber, consisting of an array of diagonally distributed double-sized disks on a silica-coated gold film. We find this structure can generate the superposition of three resonant absorption peaks to broaden the absorption band. The finite element simulation (FES) results show that the absorption bandwidth can be adjusted from 2.63 to 5.04 THz by simply changing the sizes of the disks. In addition, the peak absorptance can be continuously regulated from 9.8% to 96% by varying the conductivity of . Finally, the absorber is polarization-insensitive and has wide-angle absorption. The wide absorption band and adjustable bandwidth of the absorbers have important applications potentially for intelligent stealth materials.
结合相变的太赫兹吸收体是一类具有可调吸收率的隐身材料。然而，这类吸收体仍存在吸收带宽不足的问题。我们提出了一种三层太赫兹（THz）吸收体，它由二氧化硅涂层金膜上对角分布的双倍尺寸圆盘阵列组成。我们发现这种结构可以产生三个共振吸收峰的叠加，从而拓宽吸收带。有限元模拟（FES）结果表明，通过简单改变圆盘的尺寸，吸收带宽可从2.63太赫兹调整到5.04太赫兹。此外，通过改变圆盘的电导率，峰值吸收率可在9.8%至96%之间连续调节。最后，该吸收体对偏振不敏感且具有广角吸收特性。吸收体的宽吸收带和可调带宽在智能隐身材料方面具有重要的潜在应用。
