Passive Acoustic Metasurface with Unitary Reflection Based on Nonlocality

Li Quan and Andrea Alù

Phys. Rev. Applied 11, 054077 – Published 28 May 2019

Abstract

Metasurfaces have introduced large flexibility in manipulating the impinging wavefront for light and sound by locally engineering the reflection and transmission coefficients based on generalized Snell’s laws. Local phenomena in each unit cell, however, are fundamentally limited in the level of efficiency with which anomalous wavefront transformations can be achieved. Here, we explore acoustic metasurfaces with suitably engineered nonlocality, obtained by coupling neighboring cells. We demonstrate that nonlocal passive metastructures can overcome the limitations of local designs, and mimic balanced gain and loss distributions, enabling unitary efficiency for extreme beam steering.

Received 11 March 2019
Revised 15 April 2019

DOI:https://doi.org/10.1103/PhysRevApplied.11.054077

Physics Subject Headings (PhySH)

Acoustic metamaterials Acoustic wave phenomena Beam control Beam optics Light propagation, transmission & absorption

Interdisciplinary PhysicsGeneral Physics

Authors & Affiliations

Li Quan¹ and Andrea Alù^1,2,3,4,*

¹Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
²Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, USA
³Physics Program, Graduate Center, City University of New York, New York, New York 10026, USA
⁴Department of Electrical Engineering, City College of New York, New York, New York 10031, USA