Specific multiple-scattering process in acoustic cloak with multilayered homogeneous isotropic materials

It was qualitatively demonstrated through finite-element full-wave simulations that acoustic cloak can be constructed by using concentric multilayered structure with alternating homogeneous isotropic materials [Y. Cheng et al., Appl. Phys. Lett. 92, 151913 (2008)]. Here we present a sequential in-depth analysis of the proposed cloak by means of the multiple-scattering algorithms. Calculated pressure fields demonstrate that the cloak possesses low-reflection and wavefront-bending properties. The scattering patterns further characterize the directional cloaking performance in the far field, which is consistent with the pressure fields. The mechanism of the cloaking is ascribed to a specific multiple-scattering process determined by the microscopic material distribution and structural details of the cloak. We also discuss the behavior of the multilayered cloak as a function of wavelength.