An electrically tunable metasurface integrated with graphene for mid-infrared light modulation

We propose a low-cost plasmonic metasurface integrated with single-layer graphene for dynamic modulation of midinfrared light. The plasmonic metasurface is composed of an array of split magnetic resonators(MRs) where a nano slit is included. Extraordinary optical transmission(EOT) through the deep subwavelength slit is observed by excitation of magnetic plasmons in the split MRs. Furthermore, the introduction of the slit provides strongly enhanced fields around the graphene layer, leading to a large tuning effect on the EOT by changing the Fermi energy of the graphene. The proposed metasurface can be utilized as an optical modulator with a broad modulation width(15 μm) or an optical switch with a high on/off ratio( 100). Meanwhile, the overall thickness of the metasurface is 430 nm, which is tens of times smaller than the operating wavelength. This work may have potential applications in mid-infrared optoelectrical devices and give insights into reconfigurable flat optics and optoelectronics.     

异质结光催化材料的新进展

伴随着人类文明的快速发展,一些危机慢慢显露出来,例如能源危机、环境污染和全球变暖.2019年5月11日,Mauna Loa天文台报告,大气中的二氧化碳水平超过415 ppm,达到人类历史上的最高记录,欧盟随后于2019年11月宣布了气候紧急状态.因此,绿色能源技术已成为迫切需求,以减少化石燃料的使用,并减少污染物的产生...