Propagation Characteristics of Vortex Beam Using Visualization Analysis in Free Space

2021 ◽  
Vol 16 (5) ◽  
pp. 838-843
Author(s):  
Yan Zhang ◽  
Minru Hao ◽  
Min Shao ◽  
Yunzhe Zhang
Keyword(s):  
Optical Communication ◽  
Free Space ◽  
Simulation Analysis ◽  
Propagation Distance ◽  
Momentum Density ◽  
Linear Momentum ◽  
Propagation Characteristics ◽  
Transverse Profile ◽  
Vortex Beams ◽  
Topological Charges

We theoretically analyze the linear momentum density and orbital angular momentum (OAM) propagation characteristics of Gaussian vortex beams in free space, and perform detailed numerical simulation analysis of the linear momentum density and OAM propagation characteristics. Further, we study the variation of the propagation characteristics with different topological charges. In addition, we also analyzed the position of momentum in the transverse profile, where the momentum density of the spot will be broadened with propagation distance. This study can provide guidance for using vortex beams in optical communication and manipulation.

scholarly journals Acoustic Bessel Vortex Beam by Quasi-Three-Dimensional Reflected Metasurfaces

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1388
Author(s):  
Yin Wang ◽  
Jiao Qian ◽  
Jian-Ping Xia ◽  
Yong Ge ◽  
Shou-Qi Yuan ◽  
...  
Keyword(s):  
Free Space ◽  
High Performance ◽  
Three Dimensional ◽  
Propagation Distance ◽  
Vortex Beam ◽  
Remote Communication ◽  
Long Distance ◽  
Broad Bandwidth ◽  
Vortex Beams ◽  
Distance Propagation

Vortex beams have a typical characteristic of orbital angular momentum, which provides a new degree of freedom for information processing in remote communication and a form of non-contact manipulation for trapping particles. In acoustics, vortex beams are generally observed on the surface of a metamaterial structure or in a waveguide with a hard boundary owing to the characteristic of easy diffusion in free space. The realization of an acoustic vortex beam with a long-distance propagation in free space still remains a challenge. To overcome this, we report a type of acoustic Bessel vortex (ABV) beam created by a quasi-three-dimensional reflected metasurface in free space based on phase modulation. By using the Bessel and vortex phase profiles, we can realize an ABV beam with the high performances of both Bessel and vortex beams, and its effective propagation distance is larger than 9.2λ in free space. Beyond that, we discuss the bandwidth and topological charge of the ABV beam in detail, and the fractional bandwidth can reach about 0.28. The proposed ABV beam has the advantages of a high-performance vortex, long-distance propagation, and broad bandwidth, which provide a new pathway for designing multifunctional vortex devices with promising applications.

Study on Propagation Characteristics of EM Wave of PD in Cable Accessories

2013 ◽  
Vol 325-326 ◽  
pp. 610-614
Author(s):  
Qian Shi ◽  
Feng Wang ◽  
Ting Ting Fu ◽  
Yan Miao
Keyword(s):  
High Frequency ◽  
Simulation Analysis ◽  
Propagation Distance ◽  
Signal Propagation ◽  
Pulse Frequency ◽  
Three Dimension ◽  
Propagation Characteristics ◽  
Detection Distance ◽  
Tem Mode ◽  
Composite Interfaces

PD in cable accessories will inspire EM waves of ultra-high frequency (UHF) at hundreds of MHZ to GHZ. To study the characteristics of EM wave inspired by PD in cable accessories, a three-dimension model of 110kV cable joints is established. Based on the propagation theory of EM waves in coaxial waveguide, finite element method (FEM) is used to analyze the effect of cable joints composite interfaces on UHF signal propagation, and simulation analysis of relations between PD UHF signal's energy distribution, pulse frequency, propagation distance. Simulation results show that the main transmission mode of EM waves is TEM mode in the joints; Energy of EM waves descends rapidly as the PD pulse's frequency increases; Energy of TEM waves descends rapidly with the increasing detection distance. Simulation analysis of UHF signal's propagation characteristics provides the theoretical basis for UHF PD detection in cable accessories.

Sign in / Sign up

Export Citation Format

Share Document