Department of Physics, The Blackett Laboratory, Imperial College London , London SW7 2AZ, United Kingdom.
ACS Nano. 2018 Feb 27;12(2):1006-1013. doi: 10.1021/acsnano.7b07951. Epub 2018 Jan 23.
By exploiting singular spatial modulations of the graphene conductivity, we design a broadband, tunable THz absorber whose efficiency approaches the theoretical upper bound for a wide absorption band with a fractional bandwidth of 185%. Strong field enhancement is exhibited by the modes of this extended structure, which is able to excite a wealth of high-order surface plasmons, enabling deeply subwavelength focusing of incident THz radiation. Previous studies have shown that the conductivity can be modulated at GHz frequencies, which might lead to the development of efficient high-speed broadband switching by an atomically thin layer.
通过利用石墨烯电导率的奇异空间调制，我们设计了一种宽带、可调谐的太赫兹吸收器，其效率接近具有 185%分数带宽的宽吸收带的理论上限。通过扩展结构的模式显示出强场增强，这能够激发大量的高阶表面等离子体，实现入射太赫兹辐射的深亚波长聚焦。先前的研究表明，电导率可以在 GHz 频率下调制，这可能导致通过原子层实现高效高速宽带切换。
