Jia Delin, Xu Jia, Yu Xiaomei
Opt Express. 2018 Oct 1;26(20):26227-26234. doi: 10.1364/OE.26.026227.
In this paper, we demonstrate an ultra-broadband terahertz (THz) bi-metasurfaces absorber composed of two stacking metasurfaces backed by a metallic ground plane. The bottom metasurface consists of four multiplexed cross resonators with different geometries on a thin parylene layer, achieving a bandwidth of 3.80 THz with the absorption higher than 50% at high frequency. Meanwhile, the top metasurface, including two multiplexed cross resonators with different sizes on a relatively thicker parylene layer, provides a low frequency absorption band with an additional Salisbury screen absorption peak that connects the two absorption bands of the two metasurfaces, therefore enabling an ultra-broadband absorption. The experimental absorption spectrum of the bi-metasurfaces shows a bandwidth of 4.46 THz while the absorption exceeding 50% and a full width at half maxima (FWHM) of 97.7%. The ultra-broadband absorber will be a promising candidate for THz broadband detection.
在本文中，我们展示了一种由两个堆叠的超表面组成的超宽带太赫兹（THz）双超表面吸收器，其背面为金属接地平面。底部超表面由在薄聚对二甲苯层上具有不同几何形状的四个复用交叉谐振器组成，在高频下实现了3.80太赫兹的带宽，吸收高于50%。同时，顶部超表面包括在相对较厚的聚对二甲苯层上的两个具有不同尺寸的复用交叉谐振器，提供了一个低频吸收带以及一个额外的等效全向反射器吸收峰，该峰连接了两个超表面的两个吸收带，从而实现了超宽带吸收。双超表面的实验吸收光谱显示带宽为4.46太赫兹，吸收超过50%，半高宽（FWHM）为97.7%。这种超宽带吸收器将是太赫兹宽带检测的一个有前途的候选者。
