Sang Tian, Gao Jian, Yin Xin, Qi Honglong, Wang La, Jiao Hongfei
Department of Photoelectric Information Science and Engineering, School of Science, Jiangnan University, Wuxi, 214122, China.
Key Laboratory of Advanced Micro-Structured Materials MOE, Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China.
Nanoscale Res Lett. 2019 Mar 20;14(1):105. doi: 10.1186/s11671-019-2937-7.
An angle-insensitive broadband absorber of graphene covering the whole visible spectrum is numerically demonstrated, which is resulted from multiple couplings of the electric and magnetic dipole resonances in the narrow metallic grooves. This is achieved by integrating the graphene sheet with a multi-grooved metasurface separated by a polymethyl methacrylate (PMMA) spacer, and an average absorption efficiency of 71.1% can be realized in the spectral range from 450 to 800 nm. The location of the absorption peak of graphene can be tuned by the groove depth, and the bandwidth of absorption can be flexibly controlled by tailoring both the number and the depth of the groove. In addition, broadband light absorption enhancement of graphene is robust to the variations of the structure parameters, and good absorption properties can be maintained even the incident angle is increased to 60°.
数值演示了一种覆盖整个可见光谱的石墨烯角度不敏感宽带吸收器，它是由窄金属凹槽中电偶极子和磁偶极子共振的多重耦合产生的。这是通过将石墨烯片与由聚甲基丙烯酸甲酯（PMMA）间隔层隔开的多槽超表面集成实现的，在450至800nm的光谱范围内可实现71.1%的平均吸收效率。石墨烯吸收峰的位置可通过凹槽深度进行调节，吸收带宽可通过调整凹槽数量和深度灵活控制。此外，石墨烯的宽带光吸收增强对结构参数的变化具有鲁棒性，即使入射角增加到60°，也能保持良好的吸收特性。
