Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
Journal Home About Issues in Progress Current Issue All Issues Feature Issues

Phase-engineered metalenses to generate converging and non-diffractive vortex beam carrying orbital angular momentum in microwave region

Kuang Zhang, Yueyi Yuan, Dawei Zhang, Xumin Ding, Badreddine Ratni, Shah Nawaz Burokur, Manjun Lu, Kun Tang, and Qun Wu

Open Access Open Access

Abstract

In this paper, ultra-thin metalenses are proposed to generate converging and non-diffractive vortex beam carrying orbital angular momentum (OAM) in microwave region. Phase changes are introduced to the transmission cross-polarized wave by tailoring spatial orientation of Pancharatnam-Berry phase unit cell. Based on the superposition of phase profile of spiral phase plate and that of a converging lens or an axicon, vortex beam carrying OAM mode generated by the metalens can also exhibit characteristics of a focusing beam or a Bessel beam. Measured field intensities and phase distributions at microwave frequencies verify the theoretical design procedure. The proposed method provides an efficient approach to control the radius of vortex beam carrying OAM mode in microwave wireless applications for medium-short range distance.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Full Article  |  PDF Article
More Like This
Phase-modulation based transmitarray convergence lens for vortex wave carrying orbital angular momentum

Yingfan Meng, Jianjia Yi, Shah Nawaz Burokur, Lei Kang, Hailin Zhang, and Douglas H. Werner
Opt. Express 26(17) 22019-22029 (2018)

Full control of conical beam carrying orbital angular momentum by reflective metasurface

Guowen Ding, Ke Chen, Tian Jiang, Boyu Sima, Junming Zhao, and Yijun Feng
Opt. Express 26(16) 20990-21002 (2018)

Orbital angular momentum generation method based on transformation electromagnetics

Rui Feng, Jianjia Yi, Shah Nawaz Burokur, Lei Kang, Hailin Zhang, and Douglas H. Werner
Opt. Express 26(9) 11708-11717 (2018)

View More...

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (5)
Fig. 1
Fig. 1 (a) Schematic principle of the metalens generating focusing vortex beam with OAM mode. The inset shows the unit cell structure where the lattice period a = 11.1 mm, the thickness of substrate with relative permittivity εr = 2.2 is w = 2 mm, and θ is the rotation angle of unit cell. (b) Simulated transmission coefficients of the cross-polarized component. (c) Phase changes of the unit cells with different rotation angles under circularly polarized incidence.

Download Full Size | PDF

Fig. 2
Fig. 2 Simulation and measurement results of the transmitted cross-polarized wave emitted from the metalens generating pure vortex beam and converging vortex beam with topological charge of 3, and photograph of measurement setup. (a) Simulated distribution of energy in xoz plane and xoy plane for (b) z = 5λ0 and (c) z = 1.67λ0 for pure vortex beam. (d) Simulated distributions of energy at xoz plane and xoy plane for (e) z = 5λ0 and (f) z = 1.67λ0 for converging vortex beam. The insets show the simulated phase distribution in corresponding xoy planes. (g) Measured distributions of energy in xoz plane and xoy plane for (h) z = 5λ0 and (i) z = 1.67λ0 for pure vortex beam. (j) Measured distribution of energy in xoz plane and xoy plane for (k) z = 5λ0 and (l) z = 1.67λ0 for converging vortex beam. The insets show the measured phase distribution in corresponding xoy plane. (m) The top view and (n) front view of the measurement setup, the distance between horn antenna and fabricated metalens d > 10λ0.

Download Full Size | PDF

Fig. 3
Fig. 3 Simulation and measurement results of the transmitted cross-polarized wave emitted from metalens generating non-diffracting vortex beam with OAM mode having a topological charge of 1. (a) Simulated energy distribution in the xoz plane and xoy plane for (b) z = 10λ0, (c) z = 16.7λ0 and (d) z = 23.3λ0. The insets show simulated phase distribution in the corresponding xoy planes. (e) Measured energy distribution in xoz plane and xoy plane for (f) z = 5λ0, and (g) z = 20λ0. The insets show measured phase distribution in the corresponding xoy planes.

Download Full Size | PDF

Fig. 4
Fig. 4 Normalized energy intensity of Bessel-like OAM beam and Laguerre-Gaussian beam generated by metalenses with the same diameter in xoy planes for (a) z = 26λ0, (b) z = 50λ0 and (c) z = 100λ0.

Download Full Size | PDF

Fig. 5
Fig. 5 Efficiency of metalenses generating converging vortex beam and non-diffraction vortex beam.

Download Full Size | PDF

Equations (4)

Equations on this page are rendered with MathJax. Learn more.

| E → o u t 〉 = η E | E → i n 〉 + ( η R e ± i ⋅ 2 θ | R → 〉 + η L e ∓ i ⋅ 2 θ | L → 〉 )
φ l ( x , y ) = l ⋅ arc tan ( y / x )
θ O A M + C o n v ( x , y ) = 1 2 [ l ⋅ arc tan ( y / x ) + π ( f 2 + ( x 2 + y 2 ) − | f | ) / λ 0 ]
θ O A M + B e s s e l ( x , y ) = 1 2 [ l ⋅ arc tan ( y x ) + x 2 + y 2 sin β ]
Select as filters
Select Topics Cancel
Top
       
© Copyright 2024 | Optica Publishing Group. All rights reserved, including rights for text and data mining and training of artificial technologies or similar technologies.
Privacy | Terms of Use