Dynamically controllable plasmon induced transparency based on hybrid metal-graphene metamaterials

Xicheng Yan,Xiaoyun Jiang,Tingting Liu,Tao Wang,Le Cheng,Shuyuan Xiao,Haowen Hou

doi:10.1038/s41598-017-14328-6

Abstract

Novel hybrid metal-graphene metamaterials featuring dynamically controllable single, double and multiple plasmon induced transparency (PIT) windows are numerically explored in the terahertz (THz) regime. The designed plasmonic metamaterials composed of a strip and a ring with graphene integration generate a novel PIT window. Once the ring is divided into pairs of asymmetrical arcs, double PIT windows both with the spectral contrast ratio 100% are obtained, where one originates from the destructive interference between bright-dark modes, and the other is based on the interaction of bright-bright modes. Just because the double PIT windows are induced by two different mechanisms, the continuously controllable conductivity and damping of graphene are employed to appropriately interpret the high tunability in double transparency peaks at the resonant frequency, respectively. Moreover, multiple PIT windows can be achieved by introducing an additional bright mode to form the other bright-bright modes coupling. At the PIT transparent windows, the dispersions undergo tremendous modifications and the group delays reach up to 43 ps, 22 ps, and 25 ps, correspondingly. Our results suggest the existence of strong interaction between the monolayer graphene layer and metal-based resonant plasmonic metamaterials, which may hold widely applications in filters, modulators, switching, sensors and optical buffers.

Highlights

Induced transparency (EIT) effect, which is produced by the quantum destructive interference between the two excitation pathways in laser-activated multiple level atomic systems[1], has shown enormous potentials in the field of optical data storage[2] and nonlinear optical enhancement[3]
Motivated by the previous observations, we investigate the dynamically controllable single, double and multiple plasmon induced transparency (PIT) effects based on hybrid metal-graphene metamaterials by varying the Fermi energy in graphene, which consist of a strip and a ring with graphene integration structure
We propose dynamically controllable single, double and multiple PIT windows based on hybrid metal-graphene metamaterials consisting of a strip and a ring with graphene integration by tailoring the Fermi energy of graphene

Summary

Introduction

Induced transparency (EIT) effect, which is produced by the quantum destructive interference between the two excitation pathways in laser-activated multiple level atomic systems[1], has shown enormous potentials in the field of optical data storage[2] and nonlinear optical enhancement[3]. Motivated by the previous observations, we investigate the dynamically controllable single, double and multiple PIT effects based on hybrid metal-graphene metamaterials by varying the Fermi energy in graphene, which consist of a strip and a ring with graphene integration structure. Both the strip and the ring are served as bright modes, which are induced by electric dipole oscillations. Compared with previously PIT effects, our structured plasmonic metamaterials presented have high feasibility and easy modulation

Methods

Results

Conclusion