摘要
Vortex wave and plane wave,as two most fundamental forms of wave propagation,are widely applied in various research fields.However,there is currently a lack of basic mechanism to enable arbitrary conversion between them.In this paper,we propose a new paradigm of extremely anisotropic acoustic metasurface(AM)to achieve the efficient conversion from 2D vortex waves with arbitrary orbital angular momentum(OAM)to plane waves.The underlying physics of this conversion process is ensured by the symmetry shift of AM medium parameters and the directional compensation of phase.Moreover,this novel phenomenon is further verified by analytical calculations,numerical demonstrations,and acoustic experiments,and the deflection angle and direction of the converted plane waves are qualitatively and quantitatively confirmed by a simple formula.Our work provides new possibilities for arbitrary manipulation of acoustic vortex,and holds potential applications in acoustic communication and OAM-based devices.
基金
This work was supported by the National Key Research and Development Program of China(Grant No.2020YFA0710100)
the National Natural Science Foundation of China(Grant Nos.92050102 and 12374410)
the Fundamental Research Funds for the Central Universities(Grant Nos.20720220033 and 20720230102)
China Scholarship Council(No.202106310002).
