A perfect Fresnel acoustic reflector implemented by a Fano-resonant metascreen

Amin, M.; Siddiqui, O.; Farhat, Mohamed; Khelif, A.

A perfect Fresnel acoustic reflector implemented by a Fano-resonant metascreen

Files

1.5012012.pdf (2.84 MB)

Type

Article

Authors

Amin, M.
Siddiqui, O.
Farhat, Mohamed
Khelif, A.

KAUST Department

Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division

Online Publication Date

2018-04-10

Print Publication Date

2018-04-14

Date

2018-04-10

Abstract

We propose a perfectly reflecting acoustic metasurface which is designed by replacing the curved segments of the traditional Fresnel reflector by flat Fano-resonant sub-wavelength unit cells. To preserve the original Fresnel focusing mechanism, the unit cell phase follows a specific phase profile which is obtained by applying the generalized Snell's law and Fermat's principle. The reflected curved phase fronts are thus created at the air-metasurface boundary by tailoring the metasurface dispersion as dictated by Huygens' principle. Since the unit cells are implemented by sub-wavelength double slit-shaped cavity resonators, the impinging sound waves are perfectly reflected producing acoustic focusing with negligible absorption. We use plane-wave solution and full-wave simulations to demonstrate the focusing effects. The simulation results closely follow the analytical predictions.

Citation

Amin M, Siddiqui O, Farhat M, Khelif A (2018) A perfect Fresnel acoustic reflector implemented by a Fano-resonant metascreen. Journal of Applied Physics 123: 144502. Available: http://dx.doi.org/10.1063/1.5012012.