Conformally Mapped Multifunctional Acoustic Metamaterial Lens for Spectral Sound Guiding and Talbot Effect
The acoustic metamaterial Mikaelian lens. (a) The two-dimensional cross-channel acoustic metamaterial. For each unit cell, length and thickness . Slit opening size is used to tune the refractive index. (b) Change of refractive index with the metamaterial unit cell slit opening size . (c) The perfect refractive index profile of Mikaelian lens and discrete indices used for sample fabrication. (d) The fabricated sample. It is comprised of 36 rows and 50 columns. The height of the cells and the thickness of the polymethyl methacrylate plate . On the left is the top view schematic of the 18 discrete unit cells in the red box; the inset is the detail view of the sample structure.