Control of the Spin Angular Momentum and Orbital Angular Momentum of a Reflected Wave by Multifunctional Graphene Metasurfaces
Chen Zhang,
Li Deng,
Jianfeng Zhu,
Weijun Hong,
Ling Wang,
Wenjie Yang,
Shufang Li
Affiliations
Chen Zhang
Beijing Key Laboratory of Network System Architecture and Convergence, Beijing Laboratory of Advanced Information Network, Beijing University of Posts and Telecommunications, 10 Xitucheng Road, Beijing 100876, China
Li Deng
Beijing Key Laboratory of Network System Architecture and Convergence, Beijing Laboratory of Advanced Information Network, Beijing University of Posts and Telecommunications, 10 Xitucheng Road, Beijing 100876, China
Jianfeng Zhu
Beijing Key Laboratory of Network System Architecture and Convergence, Beijing Laboratory of Advanced Information Network, Beijing University of Posts and Telecommunications, 10 Xitucheng Road, Beijing 100876, China
Weijun Hong
Beijing Key Laboratory of Network System Architecture and Convergence, Beijing Laboratory of Advanced Information Network, Beijing University of Posts and Telecommunications, 10 Xitucheng Road, Beijing 100876, China
Ling Wang
Beijing Key Laboratory of Network System Architecture and Convergence, Beijing Laboratory of Advanced Information Network, Beijing University of Posts and Telecommunications, 10 Xitucheng Road, Beijing 100876, China
Wenjie Yang
Beijing Key Laboratory of Network System Architecture and Convergence, Beijing Laboratory of Advanced Information Network, Beijing University of Posts and Telecommunications, 10 Xitucheng Road, Beijing 100876, China
Shufang Li
Beijing Key Laboratory of Network System Architecture and Convergence, Beijing Laboratory of Advanced Information Network, Beijing University of Posts and Telecommunications, 10 Xitucheng Road, Beijing 100876, China
Three kinds of multifunctional graphene metasurfaces based on Pancharatnam–Berry (PB) phase cells are proposed and numerically demonstrated to control a reflected wave’s spin angular momentum (SAM) and orbital angular momentum (OAM) in the terahertz (THz) regime. Each proposed metasurface structure is composed of an array of graphene strips with different deviation angles and a back-grounded quartz substrate. In order to further help readers have a deeper insight into the graphene-based metasurfaces, a detailed design strategy is also provided. With the aid of the designed graphene elements, the proposed metasurfaces can achieve the full 360° range of phase coverage and provide manipulation of SAM and OAM of a circularly polarized (CP) wave at will. More importantly, simultaneous control of these two momentums can also be realized, and in order to demonstrate this function, a THz spin-controlled OAM beam generator with diverse topological charges is created, which can provide one more degree of freedom to improve the channel capability without increasing the bandwidth compared to a linearly polarized (LP) OAM beam. Numerical results verify the proposed graphene metasurfaces, which pave the way for generating spin OAM vortex waves for THz communication systems.
