Free-space information transfer using the elliptic vortex beam with fractional topological charge

2019 ◽  
Vol 431 ◽  
pp. 238-244 ◽  
Author(s):  
Xiaohui Zhang ◽  
Tian Xia ◽  
Shubo Cheng ◽  
Shaohua Tao
Keyword(s):  
Free Space ◽  
Topological Charge ◽  
Information Transfer ◽  
Vortex Beam

Free Space Realization of the Symmetrical Tunable Auto‐Focusing Lommel Gaussian Vortex Beam

2021 ◽  
pp. 2100419
Author(s):  
Jialong Tu ◽  
Xinyue Wang ◽  
Xing Yu ◽  
Haonan Wang ◽  
Dongmei Deng
Keyword(s):  
Free Space ◽  
Vortex Beam ◽  
Space Realization ◽  
Auto Focusing

Generation and characterization of a perfect vortex beam with a large topological charge through a digital micromirror device

2015 ◽  
Vol 54 (27) ◽  
pp. 8030 ◽  
Author(s):  
Yue Chen ◽  
Zhao-Xiang Fang ◽  
Yu-Xuan Ren ◽  
Lei Gong ◽  
Rong-De Lu
Keyword(s):  
Topological Charge ◽  
Vortex Beam ◽  
Digital Micromirror Device

Nonparaxial properties of partially coherent Lorentz-Gauss vortex beam propagating in free space

Optik ◽  
2018 ◽  
Vol 165 ◽  
pp. 148-158 ◽  
Author(s):  
Yan Yin ◽  
Dajun Liu ◽  
Yaochuan Wang
Keyword(s):  
Free Space ◽  
Vortex Beam ◽  
Partially Coherent

Multi-channeled vortex beam switch with moiré metasurfaces

2021 ◽  
Author(s):  
Cheng Cui ◽  
Zheng Liu ◽  
Bin Hu ◽  
Yurong Jiang ◽  
Juan Liu
Keyword(s):  
Functional Diversity ◽  
Optical Communications ◽  
Topological Charge ◽  
Signal Transmission ◽  
Polarized Light ◽  
Vortex Beam ◽  
Practical Applications ◽  
Linearly Polarized ◽  
Vortex Beams ◽  
Topological Charges

Abstract Tunable metasurface devices are considered to be an important link for metasurfaces to practical applications due to their functional diversity and high adaptability to the application scenarios. Metasurfaces have unique value in the generation of vortex beams because they can realize light wavefronts of any shape. In recent years, several vortex beam generators using metasurfaces have been proposed. However, the topological charge generally lacks tunability, which reduces the scope of their applications. Here, we propose an active tunable multi-channeled vortex beam switch based on a moiré structure composed of two cascaded dielectric metasurfaces. The simulation results show that when linearly polarized light with a wavelength of 810 nm is incident, the topological charge from -6 to +6 can be continuously generated by relatively rotating the two metasurfaces. Meanwhile, different topological charges are deflected to different spatial channels, realizing the function of multi-channeled signal transmission. We also study the efficiency and broadband performance of the structure. The proposed multi-channeled separation method of vortex beams that can actively tune topological charges paves the way for the compactness and functional diversity of devices in the fields of optical communications, biomedicine, and optoelectronics.

scholarly journals Phase detection of coherence singularities and determination of the topological charge of a partially coherent vortex beam

2019 ◽  
Vol 114 (20) ◽  
pp. 201106 ◽  
Author(s):  
Xingyuan Lu ◽  
Chengliang Zhao ◽  
Yifeng Shao ◽  
Jun Zeng ◽  
Sander Konijnenberg ◽  
...  
Keyword(s):  
Topological Charge ◽  
Vortex Beam ◽  
Phase Detection ◽  
Partially Coherent ◽  
Coherent Vortex

Detecting the topological charge of a vortex beam by an arc slit diffraction

2017 ◽  
Vol 31 (23) ◽  
pp. 1750172 ◽  
Author(s):  
Dongzhi Fu ◽  
Hailong Zhou ◽  
Kaiwei Wang ◽  
Pei Zhang ◽  
Jianji Dong ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Diffraction Pattern ◽  
Orbital Angular Momentum ◽  
Topological Charge ◽  
Light Spot ◽  
Far Field ◽  
Vortex Beam ◽  
Efficient Measurement ◽  
Vortex Beams

The simple and efficient measurement of the light orbital angular momentum (OAM) is essential to both the classical and quantum applications with vortex beams. Here, we study the diffraction pattern in the far field when a vortex beam passes through an arc slit and demonstrate experimentally that a light spot of the diffraction pattern has a displacement which is linear to the topological charge (TC) of the incident vortex beam. Based on this property, this method is capable of measuring both modulus and sign of TC of the vortex beam. Furthermore, this scheme allows identifying multiple OAM states simultaneously.

scholarly journals On-Column 2p Bound State with Topological Charge ±1 Excited by an Atomic-Size Vortex Beam in an Aberration-Corrected Scanning Transmission Electron Microscope

2012 ◽  
Vol 18 (4) ◽  
pp. 711-719 ◽  
Author(s):  
Huolin L. Xin ◽  
Haimei Zheng
Keyword(s):  
Topological Charge ◽  
Bound States ◽  
Numerical Solutions ◽  
Incident Beam ◽  
Vortex Beam ◽  
Phase Front ◽  
Atomic Size ◽  
Convergence Angle ◽  
Vortex Beams ◽  
Energy Convergence

AbstractAtomic-size vortex beams have great potential in probing the magnetic moment of materials at atomic scales. However, the limited depth of field of vortex beams constrains the probing depth in which the helical phase front is preserved. On the other hand, electron channeling in crystals can counteract beam divergence and extend the vortex beam without disrupting its topological charge. Specifically, in this article, we report that atomic vortex beams with topological charge ±1 can be coupled to the 2p columnar bound states and propagate for more than 50 nm without being dispersed and losing its helical phase front. We give numerical solutions to the 2p columnar orbitals and tabulate the characteristic size of the 2p states of two typical elements, Co and Dy, for various incident beam energies and various atomic densities. The tabulated numbers allow estimates of the optimal convergence angle for maximal coupling to 2p columnar orbital. We have also developed analytic formulae for beam energy, convergence angle, and hologram-dependent scaling for various characteristic sizes. These length scales are useful for the design of pitch-fork apertures and operations of microscopes in the vortex-beam imaging mode.

scholarly journals Spiral phase plate with multiple singularity centers

2020 ◽  
Vol 44 (6) ◽  
pp. 901-908
Author(s):  
V.V. Kotlyar ◽  
A.A. Kovalev ◽  
E.S. Kozlova ◽  
A.P. Porfirev
Keyword(s):  
Topological Charge ◽  
Beam Power ◽  
Phase Plate ◽  
Circular Aperture ◽  
Vortex Beam ◽  
Finite Radius ◽  
Phase Singularity ◽  
Initial Plane ◽  
Topological Charges ◽  
Spiral Phase

We investigate a multispiral phase plate (MSPP) with multiple centers of phase singularity arbitrarily located in the MSPP plane. Equations to describe the topological charge of an optical vortex in the initial plane immediately behind the MSPP and orbital angular momentum (OAM) normalized relative to the beam power are derived. The topological charge in the initial plane is found as a sum of the topological charges of all singularities if their centers are located inside a finite-radius circular aperture. If the phase singularity centers are partially located on the boundary of a circular diaphragm limiting the MSPP, the total topological charge is found as the sum of all singularities divided by 2. Total OAM that the vortex carries depends on the location of the singularity centers: the farther from the center of the plate the singularity center is located, the smaller is its contribution to the OAM. If all singularity centers are located on the boundary of the diaphragm limiting MSPP, then the OAM of the vortex beam equals zero, although in this case the topological charge of the beam is nonzero.

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