Perfect multiple splitting with arbitrary power distribution by acoustic metasurfaces

Jiangsu Key Laboratory of Opto-Electronic Technology, School of Physics and Technology, Nanjing Normal University Nanjing 210023, China

^(a) zhuxingfeng@njnu.edu.cn (corresponding author)
^(b) wudajian@njnu.edu.cn

Received: 22 February 2021
Accepted: 30 April 2021

Abstract

The passive lossless acoustic metasurfaces (AMs) usually use nonlocal behaviors to realize high-efficiency acoustic field manipulation. However, nonlocal behaviors always need complicated unit-cell designs or structure optimizations. In this work, a simple passive lossless AM without nonlocal responses is proposed to perfectly manipulate multi-order diffraction beams. We demonstrate theoretically that the proposed AM can efficiently split an incident acoustic wave into desired reflected directions with arbitrary power flow ratio. Then two examples of two-beam and three-beam lossless AM splitters are constructed with well-designed rigidly ended tubes. Simulation results verify that nearly 100% reflection efficiency can be achieved in the two AM splitters and the power flow distributions are in accord with the designed values. Finally, we fabricate the two-beam AM splitter and confirm experimentally that it can achieve high-efficiency reflection splitting with arbitrary power distribution. Our proposed AM may contribute to designing devices for different applications in energy harvesting and communication.