Negative Refraction, Acoustical Metamaterials and Acoustical Cloaking

Abstract

An introduction is given. Then, there is an explanation of the limitation of Veselago’s theory with the following coverage: introduction, gauge invariance of homogeneous electromagnetic wave equation, gauge invariance of acoustic field equation, acoustical cloaking, gauge invariance of nonlinear homogeneous acoustic wave equation; the discovery of negative refraction is a special case of coordinate transformations or a unified theory for negative refraction and cloaking, conclusions. This is followed by the multiple scattering approach to perfect acoustic lens. Acoustical cloaking is described with introduction, derivation of transformation acoustics and application to a specific example. Acoustic metamaterial and simultaneous negative mass density and negative bulk modulus is described. Then, there is acoustical cloaking based on nonlinear coordinate transformations. Acoustical cloaking of underwater objects and extension of double negativity to nonlinear acoustics are also provided.