石墨烯等离激元在中红外到太赫兹波段有广阔应用前景。以往研究多关注于 石墨烯等离激元和基底声子的耦合,但如何调控这种耦合的报道却很少。一种可能的调控耦合的方式是改变石墨烯 条带周围的介电环境。数值模拟表明,与放置在平整二氧化硅基底上的石墨烯条带相比,放置在凹槽中的石墨烯条带 的等离激元和声子耦合增强。此外,在远离声子频率处色散曲线明显下移,低频段两个色散分支的最大光吸收率也有 显著提高。而将石墨烯条带放置在凸台上则结果相反。研究结果表明石墨烯等离激元和基底声子的耦合可以通过改 变石墨烯条带边缘介电环境这种简单方式得到有效调控。

Graphene plasmons have tremendous potential applications in middle-infrared to terahertz frequencies. Previous studies mainly focused on the coupling between graphene plasmon and phonon of substrate, while the approach to modulate such coupling has been rarely reported. One possible approach to modulate such coupling is to change the dielectric environment around graphene nanoribbons (GNRs). Numerical simulation indicates that compared with GNRs on flat SiO2 substrate, GNRs in grooves demonstrate stronger coupling between plasmon and phonon. In addition, the dispersion curve of plasmons shifts down when the frequency is away from the frequency of phonon, and the maximum absorption of the two dispersion curve branches at low frequency is also significantly improved. On the contrary, GNRs on the SiO2 protruding platform lead to contrary results. Such observations reveal that the coupling between graphene plasmon and phonon of substrate can be efficiently modulated by simply changing the edge dielectric environment of GNRs.