title: Angle- and position-insensitive electrically tunable absorption in graphene by epsilon-near-zero effect.
abstract: We propose an electrically tunable absorber based on epsilon-near-zero (ENZ) effect of graphene embedded in a nanocavity, which is composed of metal grating and substrate. Due to strong surface-normal electric field confined in ENZ graphene in the proposed structure, greatly enhanced light absorption (~80%) is achieved in an ultrathin graphene monolayer. By electrically controlling the Fermi-level of graphene, a sharp peak absorption wavelength is tuned over a wide range. The proposed device can work as an optical modulator or a tunable absorption filter, which has a unique feature of incident angle insensitiveness owing to the ENZ effect and magnetic dipole resonance. Moreover, existence of a significantly dominant electric field and its uniformity make the device performance independent of the position of the graphene layer in the nanocavity, which provides great fabrication tolerance.
authors.forename: Sangjun
authors.initials: S
authors.lastname: Lee
authors.forename: Thang Q
authors.initials: TQ
authors.lastname: Tran
authors.forename: Myunghwan
authors.initials: M
authors.lastname: Kim
authors.forename: Hyungjun
authors.initials: H
authors.lastname: Heo
authors.forename: Junseok
authors.initials: J
authors.lastname: Heo
authors.forename: Sangin
authors.initials: S
authors.lastname: Kim