An acoustic Maxwell’s fish-eye lens based on gradient-index metamaterials

Yuan Bao-guo^{1, 2}, Tian Ye¹, Cheng Ying^{1, 3, †,}, Liu Xiao-jun^{1, 3, ‡,}

(a) The variation of the n_r inside the lens as a function of r. (b) The required a-value for the AMFE lens in the radial direction. (c) The relative effective acoustic impedance Z_r for the AMFE lens with r.