title: Giant acoustic concentration by extraordinary transmission in zero-mass metamaterials.
abstract: We demonstrate 97%, 89%, and 76% transmission of sound amplitude in air through walls perforated with subwavelength holes of areal coverage fractions 0.10, 0.03, and 0.01, respectively, producing 94-, 950-, and 5700-fold intensity enhancements therein. This remarkable level of extraordinary acoustic transmission is achieved with thin tensioned circular membranes, making the mass of the air in the holes effectively vanish. Imaging the pressure field confirms incident-angle independent transmission, thus realizing a bona fide invisible wall. Applications include high-resolution acoustic sensing.
authors.affiliation: Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea.
authors.forename: Jong Jin
authors.initials: JJ
authors.lastname: Park
authors.affiliation: Department of Physics, Ewha Womans University, Seoul 120-750, Korea.
authors.forename: K J B
authors.initials: KJ
authors.lastname: Lee
authors.affiliation: Division of Applied Physics, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
authors.forename: Oliver B
authors.initials: OB
authors.lastname: Wright
authors.affiliation: Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea.
authors.forename: Myoung Ki
authors.initials: MK
authors.lastname: Jung
authors.affiliation: Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea.
authors.forename: Sam H
authors.initials: SH
authors.lastname: Lee