Open AccessPhase-modulation based transmitarray convergence lens for vortex wave carrying orbital angular momentum
Author(s) -
Yingfan Meng,
Jianjia Yi,
Shah Nawaz Burokur,
Lei Kang,
Hailin Zhang,
Douglas H. Werner
Publication year - 2018
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.022019
Subject(s) - optics , physics , optical vortex , angular momentum , axicon , vortex , gaussian beam , wavefront , wave propagation , phase modulation , beam (structure) , phase noise , classical mechanics , laser , laser beams , thermodynamics
Vortex electromagnetic (EM) waves hold promise for their ability to significantly increase the transmission capacity of wireless communication systems via the torsion resistance defined by different topological charges associated with the orbital angular momentum (OAM). However, the application of vortex waves in remote distance transmission is limited by its characteristic of divergence. In this paper, a lens based on a phase-modulation metasurface (MS) is proposed that enables vortex EM waves to converge, thereby improving their propagation performance at microwave frequencies. A phase-shift distribution on the plane of the MS is obtained based on the concept of the optical converging axicon, which can convert a Laguerre-Gaussian (LG) beam to a Bessel beam based on changing the propagation direction. Simulation results verify the ability of the MS lens to achieve OAM beam focusing, which is advantageous for enhancing the propagation directivity and increasing the gain in the main lobes of vortex waves. This is of particular importance in microwave wireless communication applications.