Graphene has great potential for enhancing light−matter interactions in a two-dimensional regime due to surface plasmons with low loss and strong light confinement.Further utilization of graphene in nanophotonics reli...Graphene has great potential for enhancing light−matter interactions in a two-dimensional regime due to surface plasmons with low loss and strong light confinement.Further utilization of graphene in nanophotonics relies on the precise control of light localization properties.Here,we demonstrate the tailoring of electromagnetic field localizations in the mid-infrared region by precisely shaping the graphene into nanostructures with different geometries.We generalize the phenomenological cavity model and employ nanoimaging techniques to quantitatively calculate and experimentally visualize the two-dimensional electromagnetic field distributions within the nanostructures,which indicate that the electromagnetic field can be shaped into specific patterns depending on the shapes and sizes of the nanostructures.Furthermore,we show that the light localization performance can be further improved by reducing the sizes of the nanostructures,where a lateral confinement of λ0/180 of the incidence light can be achieved.The electromagnetic field localizations within a nanostructure with a specific geometry can also be modulated by chemical doping.Our strategies can,in principle,be generalized to other two-dimensional materials,therefore providing new degrees of freedom for designing nanophotonic components capable of tailoring two-dimensional light confinement over a broad wavelength range.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51290271,11474364 and 51290273)the National Key Basic Research Program of China(Grant Nos.2013CB933601 and 2013YQ12034506)the Guangdong Natural Science Funds for Distinguished Young Scholars(Grant No.2014A030306017)。
文摘Graphene has great potential for enhancing light−matter interactions in a two-dimensional regime due to surface plasmons with low loss and strong light confinement.Further utilization of graphene in nanophotonics relies on the precise control of light localization properties.Here,we demonstrate the tailoring of electromagnetic field localizations in the mid-infrared region by precisely shaping the graphene into nanostructures with different geometries.We generalize the phenomenological cavity model and employ nanoimaging techniques to quantitatively calculate and experimentally visualize the two-dimensional electromagnetic field distributions within the nanostructures,which indicate that the electromagnetic field can be shaped into specific patterns depending on the shapes and sizes of the nanostructures.Furthermore,we show that the light localization performance can be further improved by reducing the sizes of the nanostructures,where a lateral confinement of λ0/180 of the incidence light can be achieved.The electromagnetic field localizations within a nanostructure with a specific geometry can also be modulated by chemical doping.Our strategies can,in principle,be generalized to other two-dimensional materials,therefore providing new degrees of freedom for designing nanophotonic components capable of tailoring two-dimensional light confinement over a broad wavelength range.
