Deep-subwavelength control of acoustic waves in an ultra-compact metasurface lens
Open Access
- 22 November 2018
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature Communications
- Vol. 9 (1), 4920
- https://doi.org/10.1038/s41467-018-07315-6
Abstract
Space-coiling acoustic metasurfaces have been largely exploited and shown their outstanding wave manipulation capacity. However, they are complex in realization and cannot directly manipulate acoustic near-fields by controlling the effective path length. Here, we propose a comprehensive paradigm for acoustic metasurfaces to extend the wave manipulations to both far- and near-fields and markedly reduce the implementation complexity with a simple structure, which consists of an array of deep-subwavelength-spaced slits perforated in a thin plate. A semi-analytical approach for such a design is established using a microscopic coupled-wave model, which reveals that the acoustic diffractive pattern at every slit exit is the sum of the initial transmission and the secondary scatterings of the coupled fields from other slits. For proof-of-concept, we examine two metasurface lenses for sound focusing within and beyond the diffraction limit. This work provides a feasible strategy for creating ultra-compact acoustic components with versatile potentials.Keywords
This publication has 48 references indexed in Scilit:
- Systematic study of the focal shift effect in planar plasmonic slit lensesNanotechnology, 2012
- Extreme Acoustic Metamaterial by Coiling Up SpacePhysical Review Letters, 2012
- Twisted optical metamaterials for planarized ultrathin broadband circular polarizersNature Communications, 2012
- Focusing of longitudinal ultrasonic waves in air with an aperiodic flat lensThe Journal of the Acoustical Society of America, 2011
- Extreme-angle broadband metamaterial lensNature Materials, 2009
- Experimental demonstration of an acoustic magnifying hyperlensNature Materials, 2009
- Planar Lenses Based on Nanoscale Slit Arrays in a Metallic FilmNano Letters, 2009
- Radiationless Electromagnetic Interference: Evanescent-Field Lenses and Perfect FocusingScience, 2007
- Optical Resonance in a Narrow Slit in a Thick Metallic ScreenPhysical Review Letters, 2001
- Light transmission through metallic channels much smaller than the wavelengthOptics Communications, 2000