Open AccessEnhancing the efficiency of graphene-based THz modulator by optimizing the Brewster angle
Author(s) -
Xingyue Li,
zhaohui zhang,
XiaoFan Zhao,
Ziyang Wang,
LuQi Tao,
Zhengyong Huang,
Ying Li,
Xianhao Wu,
Yin Li,
Yuan Yuan,
Boyang Li
Publication year - 2022
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.471208
Subject(s) - brewster's angle , graphene , terahertz radiation , brewster , optics , materials science , modulation (music) , reflection (computer programming) , optoelectronics , voltage , total internal reflection , physics , computer science , nanotechnology , quantum mechanics , acoustics , programming language
The gate-controllable electronical property of graphene provides a possibility of active tuning property for THz modulator. However, the common modulation technology which only depends on voltage cannot solve the problem of power consumption limitation in communication applications. Here, we demonstrated a Brewster angle-controlled graphene-based THz modulator, which could achieve a relatively high modulation depth with low voltage. First, we explored the complex relationships among the Brewster angles, reflection coefficients and the conductivities of graphene. Then, we further investigated the optimal incident angle selection based on the unusual reflection effect which occurs at Brewster angle. Finally, an improved scheme by dynamically adjusting the incident angle was proposed in this paper. It would make it possible that the modulator could achieve a modulation depth of more than 90% with a Fermi level as low as 0.2eV at any specific frequency in the range of 0.4THz-2.2THz. This research will help to realize a THz modulator with high-performance and ultra-low-power in quantities of applications, such as sensing and communication.