title: Reflected wavefront manipulation based on ultrathin planar acoustic metasurfaces.
abstract: The introduction of metasurfaces has renewed the Snell's law and opened up new degrees of freedom to tailor the optical wavefront at will. Here, we theoretically demonstrate that the generalized Snell's law can be achieved for reflected acoustic waves based on ultrathin planar acoustic metasurfaces. The metasurfaces are constructed with eight units of a solid structure to provide discrete phase shifts covering the full 2π span with steps of π/4 by coiling up the space. By careful selection of the phase profiles in the transverse direction of the metasurfaces, some fascinating wavefront engineering phenomena are demonstrated, such as anomalous reflections, conversion of propagating waves into surface waves, planar aberration-free lens and nondiffracting Bessel beam generated by planar acoustic axicon. Our results could open up a new avenue for acoustic wavefront engineering and manipulations.
authors.affiliation: 1] Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Department of Physics, Nanjing University, Nanjing 210093, P. R. China [2] State Key Laboratory of Acoustics, Chinese Academy of Sciences, Beijing 100190, P. R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Liang
authors.forename: Zhong-ming
authors.initials: ZM
authors.lastname: Gu
authors.forename: Xin-ye
authors.initials: XY
authors.lastname: Zou
authors.forename: Jian-chun
authors.initials: JC
authors.lastname: Cheng