Manipulating line waves in flat graphene for agile terahertz applications

Nanophotonics

article

Dia’aaldin J. Bisharat¹  Daniel F. Sievenpiper² 

[1] Department of Electronic Engineering, City University of Hong Kong;Electrical and Computer Engineering Department, University of California San Diego

关键词: graphene metasurface;    one-dimensional wave;    spin-momentum locking;    surface impedance;    terahertz photonics;   

DOI  :  10.1515/nanoph-2017-0133

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Reducing open waveguides enabled by surface waves, such as surface plasmon polaritons, to a one-dimensional line is attractive due to the potentially enhanced control over light confinement and transport. This was recently shown to be possible by simply interfacing two co-planar surfaces with complementary surface impedances, which support transverse-magnetic and transverse-electric modes, respectively. Attractively, the resultant “line wave” at the interface line features singular field enhancement and robust direction-dependent polarizations. Current implementations, however, are limited to microwave frequencies and have fixed functionality due to the lack of dynamic control. In this article, we examine the potential of using gate-tunable graphene sheets for supporting line waves in the terahertz regime and propose an adequate graphene-metasurface configuration for operation at room temperature and low voltage conditions. In addition, we show the occurrence of quasi-line wave under certain conditions of non-complementary boundaries and qualify the degradation in line wave confinement due to dissipation losses. Furthermore, we show the possibility to alter the orientation of the line wave’s spin angular momentum on demand unlike conventional surface waves. Our results on active manipulation of electromagnetic line waves in graphene could be useful for various applications including reconfigurable integrated circuits, modulation, sensing and signal processes.

【 授权许可】

CC BY