Dynamically Tunable and Multifunctional Polarization Beam Splitters Based on Graphene Metasurfaces

Gongli Xiao; Sitong Zhou; Hongyan Yang; Zhixiong Lin; Haiou Li; Xingpeng Liu; Zanhui Chen; Tangyou Sun; Peihua Wangyang; Jianqing Li

doi:10.3390/nano12173022

Dynamically Tunable and Multifunctional Polarization Beam Splitters Based on Graphene Metasurfaces

Nanomaterials (Basel). 2022 Aug 31;12(17):3022. doi: 10.3390/nano12173022.

Authors

Affiliations

¹ Guangxi Key Laboratory of Precision Navigation Technology and Application, Guilin University of Electronic Technology, Guilin 541004, China.
² Guangxi Key Laboratory of Optoelectronic Information Processing, School of Optoelectronic Engineering, Guilin University of Electronic Technology, Guilin 541004, China.
³ Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology, Macau University of Science and Technology, Macau 999078, China.

Abstract

Based on coupled-mode theory (CMT) and the finite-difference time-domain (FDTD) approach, we propose a graphene metasurface-based and multifunctional polarization beam splitter that is dynamically tunable. The structure, comprising two graphene strips at the top and bottom and four triangular graphene blocks in the center layer, can achieve triple plasma-induced transparency (PIT). In a single polarization state, the computational results reveal that synchronous or asynchronous six-mode electro-optical switching modulation may be performed by modifying the Fermi levels of graphene, with a maximum modulation degree of amplitude (MDA) of 97.6% at 5.148 THz. In addition, by varying the polarization angle, a polarization-sensitive, tunable polarization beam splitter (PBS) with an extinction ratio and insertion loss of 19.6 dB and 0.35 dB at 6.143 THz, respectively, and a frequency modulation degree of 25.2% was realized. Combining PIT with polarization sensitivity provides a viable platform and concept for developing graphene metasurface-based multifunctional and tunable polarization devices.

Keywords: graphene; metamaterials; plasmon-induced transparency; polarization beam splitter; polarization-sensitive.

Grants and funding

This research was funded by the National Natural Science Foundation of China (No. 61765004, 62165004, 61805053); the Innovation Project of GUET Graduate Education (2022YCXS047, 2021YCXS040); and the Open Fund of Foshan University, Research Fund of Guangdong Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology (2020B1212030010).