Amin Muhammad, Farhat Mohamed, Bağcı Hakan
Opt Express. 2013 Dec 2;21(24):29938-48. doi: 10.1364/OE.21.029938.
An ultra-broadband multilayered graphene absorber operating at terahertz (THz) frequencies is proposed. The absorber design makes use of three mechanisms: (i) The graphene layers are asymmetrically patterned to support higher order surface plasmon modes that destructively interfere with the dipolar mode and generate electromagnetically induced absorption. (ii) The patterned graphene layers biased at different gate voltages backed-up with dielectric substrates are stacked on top of each other. The resulting absorber is polarization dependent but has an ultra-broadband of operation. (iii) Graphene's damping factor is increased by lowering its electron mobility to 1000 cm²/Vs. Indeed, numerical experiments demonstrate that with only three layers, bandwidth of 90% absorption can be extended upto 7THz, which is drastically larger than only few THz of bandwidth that can be achieved with existing metallic/graphene absorbers.
提出了一种在太赫兹（THz）频率下工作的超宽带多层石墨烯吸收器。该吸收器的设计利用了三种机制：（i）石墨烯层采用不对称图案化，以支持高阶表面等离子体模式，该模式与偶极模式相消干涉并产生电磁诱导吸收。（ii）在不同栅极电压下偏置并由介电基板支撑的图案化石墨烯层相互堆叠。所得吸收器与偏振有关，但具有超宽带的工作特性。（iii）通过将石墨烯的电子迁移率降低到1000 cm²/Vs来提高其阻尼因子。实际上，数值实验表明，仅三层石墨烯，90%吸收带宽就可以扩展到7THz，这比现有金属/石墨烯吸收器所能实现的仅几THz的带宽要大得多。
