基于石墨烯条带的窄带中红外可调吸收超表面

Narrowband Mid-infrared Adjustable Absorption Metasurfaces Based on Graphene Strips

设计了一种具有电介质-电介质-电介质(DDD)三层结构的超窄带吸收器,该结构顶层和中层电介质被石墨烯条带和金属图层隔开.模拟结果表明,该吸收体在51.8 THz附近具有高的吸收率,石墨烯条的费米能从0eV改变为0.8eV,吸收率将从80%降到40%,并且吸收带宽从8.99nm变化到6.07nm.根据频谱操纵机制,可以通过改变各电介质层的厚度来调节共振频率和吸收带宽.此外,吸收体共振频率随入射角变化.研究结果在光学滤波器和生物化学传感方面提供潜在的应用.

An ultra-narrowband absorber with a dielectric-dielectric-dielectric(DDD) tri-layer structure is reported, which is composed of top layer separated from mid layer by graphene strips and metal pattern layers.The simulation results show that the absorber has strong absorption points near 51.8 THz.Interestingly, the absorption can be tuned from 80% to 40% by varying the Fermi energy of graphene strips from 0 eV to 0.8 eV.And the absorption bandwidth can be tuned from 8.99 nm to 6.07 nm.In According to this spectrum manipulation mechanism, the resonance wavelength and bandwidth of absorption can be tuned by changing the dielectric layer thickness.Furthermore, the absorption resonance frequency is dependent of the incidence angle. The potential applications in optical filter and bio-chemical sensing are provided.