Bianisotropic acoustic metasurfaces for independent control of reflection and transmission wave

Abstract

We propose bianisotropic acoustic metasurfaces which manipulate reflection and transmission wave-front independently. We design one-dimensional bianisotropic meta-atom controlling density (ρ), inverse of bulk modulus (B-1) and bianisotropy (ξ) near zero-index point in water, based on separation of characteristic oscillations. Through derivation of the density, bulk modulus and bianisotropy as a function of S-parameters, we show full-access to the reflection and transmission amplitude and phase in the tailored bianisotropic media. Utilizing bianisotropic meta-atom, we numerically demonstrate independent control of reflection and transmission wave. Furthermore, design process of the metasurfaces of independent manipulation of forward- and backward- reflection waves is presented.