Scattering theory derivation of a 3D acoustic cloaking shell.
Through acoustic scattering theory we derive the mass density and bulk modulus of a spherical shell that can eliminate scattering from an arbitrary object in the interior of the shell--in other words, a 3D acoustic cloaking shell. Calculations confirm that the pressure and velocity fields are smoothly bent and excluded from the central region as for previously reported electromagnetic cloaking shells. The shell requires an anisotropic mass density with principal axes in the spherical coordinate directions and a radially dependent bulk modulus. The existence of this 3D cloaking shell indicates that such reflectionless solutions may also exist for other wave systems that are not isomorphic with electromagnetics.
Cummer
Steven A
SA
Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA. cummer@ee.duke.edu
Popa
Bogdan-Ioan
BI
Schurig
David
D
Smith
David R
DR
Pendry
John
J
Rahm
Marco
M
Starr
Anthony
A