Bandwidth tunability of graphene absorption enhancement by hybridization of delocalized surface plasmon polaritons and localized magnetic plasmons

Abstract

The bandwidth-tunable absorption enhancement of monolayer graphene is theoretically studied in the near-infrared wavelengths. The monolayer graphene is placed on the silver substrate surface with a periodic array of one-dimensional slits. Two absorption peaks are found to result from the hybridization of delocalized surface plasmon polaritons and localized magnetic plasmons. The positions of absorption peaks are accurately predicted by a coupling model of double oscillators. The full width at half maximum of absorption peaks is largely tuned from about 1–200 nm by changing the array period of slits. The effect of the slit size on absorption peaks is also investigated in detail. Our work is promising in applications for photoelectric devices.

Tunable High-Sensitivity Four-Frequency Refractive Index Sensor Based on Graphene Metamaterial

“…Monolayer graphene has a unique energy band structure that results in linear energy dispersion and two crossed cones at the Dirac point, meaning that there is no bandgap. As a result, it has an ultra-high carrier mobility rate, a high specific surface area, high thermal conductivity, and unique optoelectronic properties [ 13 , 14 ]. However, the low absorptivity of monolithic homogenous graphene (approximately 2.3% absorption) makes it difficult to transform into an ideal absorber.…”