金属-石墨烯光子晶体复合结构多带光吸收器设计中金属材料的选择

研究表明,具有金属-石墨烯光子晶体-金属结构的光吸收器可实现多带吸收。这种光吸收器是在由石墨烯和介质材料构成的石墨烯光子晶体两侧加载金属层构成。所加载的金属材料的光学特性对多带吸收特性具有很大的影响。采用金属介电常数的Drude-Lorentz色散模型和传输矩阵法,比较分析了七种金属材料在可见光波段对光吸收器多带吸收特性的影响。发现金属银适合做光吸收器入射空间一侧的金属层材料,而金属铝、银、金和铜适合做衬底层材料。进一步的计算发现,只使用银做加载金属材料可实现一致性好、制作容差大、吸收带宽窄的多带光吸收器。研究结果对实际多带光吸收器的设计提供了参考。

Selection of Metal Materials in Design of Metal-Graphene Photonic Crystal Composite Structure Multi-Band Optical Absorber

It was found that the multi-band absorption properties can be achieved for a absorber with a metal-graphene photonic crystal-metal (M-GPC-M) structure. The M-GPC-M composite structure can be formed by loading two metal layers on both sides of a one-dimensional graphene photonic crystal composed of graphene and a conventional dielectric material. The optical properties of the loaded metal material have great effect on the multi-band absorption characteristics of the M-GPC-M structure. The influence of seven metal materials on the multi-band absorption characteristics in the visible band was analyzed and compared by using Drude-Lorentz dispersion model for the dielectric constant of metal and the transfer matrix method. The results show that the metal Ag is suitable as the metal layer material on the side of the incident space of the absorber, and the metals Al, Ag, Au and Cu are suitable as the substrate material. Further calculations have found that a multi-band optical absorber with good consistency, large manufacturing tolerance, and narrow absorption bandwidth can be realized by only using metal Ag as the loading metal material. The research results presented here provide a useful reference for the design of the multi-band optical absorber.