All-graphene geometric terahertz metasurfaces for generating multi-dimensional focused vortex beams

Li, Hui1; Zheng, Chenglong1; Xu, Hang1; Li, Jie1; Song, Chunyu1; Yang, Fan1; Li, Jitao1; Shi, Wei1; Zhang, Yating1; Yao, Jianquan1,2

2023-04-01

10.1016/j.optlastec.2022.108986

OPTICS AND LASER TECHNOLOGY   Impact Factor & Quartile

0030-3992

1879-2545

Simultaneously assembling the functions of lenses and phase vortices into geometric metasurfaces on an ultra -compact platform can potentially be used for light trapping and edge imaging, helping to enhance their appli-cations in polarized optical systems. Here, we propose and theoretically investigate an all-graphene geometric metasurface operating in the terahertz (THz) band for generating multidimensional vortices. Focused scalar vortex beams with polarization-independent properties can be generated by introducing the superposition of two helical phases with the same topological charge within orthogonal circularly polarized (CP) channels. Focus shift can be further tolerated by tailoring the conventional helical phase distribution. Embedding polarization mod-ulation into the proposed design enables the generation of multiple focused vortices with inhomogeneous po-larization properties in the longitudinal direction. The typical conjugate phase is capable of generating aggregated vortices with vectorial characteristics by switching the incident polarization mode, and can be extended to arbitrary orders. Using the way in which the graphene Fermi energy was changed in the simulation provides strong evidence for dynamically tuning the focusing efficiency of the generated beam. Benefiting from the proposed method that manipulates the orthogonal CP components separately, the design scheme has greater degree of freedom and can find potential applications in meta-optics, high-tolerance edge imaging, and high -capacity optical communications.

Geometric metasurface Focused vortex beam Polarization multiplexing Vector vortex beams

SCI

English

Corresponding

National Key Research and Development Program of China["2021YFB2800700","2017YFA0700202"] ; National Natural Science Foundation of China (NSFC)["61735010","62075159","61975146","62105240"] ; Basic Research Program of Shenzhen[JCYJ20170412154447469]

Optics ; Physics

Optics ; Physics, Applied

WOS:000905018000004

ELSEVIER SCI LTD

ENGINEERING

2-s2.0-85143698120

Web of Science

1.Tianjin Univ, Minist Educ, Sch Precis Instruments & Optoelect Engn, Key Lab Optoelect Informat Technol, Tianjin 300072, Peoples R China
2.South Univ Sci & Technol China, Dept Elect & Elect Engn, Shenzhen 518055, Peoples R China

Li, Hui,Zheng, Chenglong,Xu, Hang,et al. All-graphene geometric terahertz metasurfaces for generating multi-dimensional focused vortex beams[J]. OPTICS AND LASER TECHNOLOGY,2023,159.

Li, Hui.,Zheng, Chenglong.,Xu, Hang.,Li, Jie.,Song, Chunyu.,...&Yao, Jianquan.(2023).All-graphene geometric terahertz metasurfaces for generating multi-dimensional focused vortex beams.OPTICS AND LASER TECHNOLOGY,159.

Li, Hui,et al."All-graphene geometric terahertz metasurfaces for generating multi-dimensional focused vortex beams".OPTICS AND LASER TECHNOLOGY 159(2023).