Open AccessAngle- and position-insensitive electrically tunable absorption in graphene by epsilon-near-zero effect
Author(s) -
Sang-Jun Lee,
Thang Q. Tran,
Myung–Hwan Kim,
Hyungjun Heo,
Junseok Heo,
Sangin Kim
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.033350
Subject(s) - graphene , materials science , optics , optoelectronics , electric field , absorption (acoustics) , grating , ray , dipole , substrate (aquarium) , nanotechnology , physics , oceanography , quantum mechanics , geology , composite material
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.