Acoustic Bessel Vortex Beam by Quasi-Three-Dimensional Reflected Metasurfaces
Yin Wang,
Jiao Qian,
Jian-Ping Xia,
Yong Ge,
Shou-Qi Yuan,
Hong-Xiang Sun,
Xiao-Jun Liu
Affiliations
Yin Wang
Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, School of Computer Science and Communication Engineering, Jiangsu University, Zhenjiang 212013, China
Jiao Qian
Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, School of Computer Science and Communication Engineering, Jiangsu University, Zhenjiang 212013, China
Jian-Ping Xia
Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, School of Computer Science and Communication Engineering, Jiangsu University, Zhenjiang 212013, China
Yong Ge
Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, School of Computer Science and Communication Engineering, Jiangsu University, Zhenjiang 212013, China
Shou-Qi Yuan
Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, School of Computer Science and Communication Engineering, Jiangsu University, Zhenjiang 212013, China
Hong-Xiang Sun
Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, School of Computer Science and Communication Engineering, Jiangsu University, Zhenjiang 212013, China
Xiao-Jun Liu
Collaborative Innovation Center of Advanced Microstructures, Key Laboratory of Modern Acoustics, Department of Physics, Nanjing University, Nanjing 210093, China
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.
