Open AccessOut-of-plane focusing and manipulation of terahertz beams based on a silicon/copper grating covered by monolayer graphene
Author(s) -
Jianli Jiang,
Xiao Zhang,
Wei Zhang,
Shuang Liang,
Hong Wu,
Liyong Jiang,
Xiangyin Li
Publication year - 2017
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.25.016867
Subject(s) - terahertz radiation , graphene , materials science , grating , optics , optoelectronics , silicon , surface plasmon polariton , plasmon , surface plasmon , nanotechnology , physics
We report new models for out-of-plane focusing and manipulation of terahertz beams based on a silicon/copper grating covered by monolayer graphene. Dependences of focusing and manipulation of terahertz beams on the chemical potential and scattering rate of graphene are investigated. Based on the graphene/silicon grating model, we demonstrate that the focal distance and intensity are sensitively influenced by the chemical potential. Based on the graphene/copper grating model, we show how 2 to 1 and 3 to 1 modulation of terahertz beams can be efficiently realized through tuning the chemical potential of graphene. These tunable beam focusing and manipulation effects are well explained by the diffraction theory of optical images and the surface plasmon polariton theory of graphene. Our proposed devices are of compact structures, high electro-optical tunability and good repeatability, and they are expected to have prospective applications in terahertz communications, imaging, sensing, and so on.