Highly Efficient Generation of Angular Momentum with Cylindrical Bianisotropic Metasurfaces

Abstract

Recent advances in metasurfaces have shown the importance of controlling the\nbianisotropic response of the constituent meta-atoms for maximum efficiency\nwavefront transformation. Under the paradigm of a bianisotropic metasurface,\nfull control of the local scattering properties is allowed opening new design\navenues for creating reciprocal metasurfaces. Despite recent advances in the\nperfect transformation of both electromagnetic and acoustic plane waves, the\nimportance of bianisotropic metasurfaces for transforming cylindrical waves is\nstill unexplored. Motivated by the possibility of arbitrarily controlling the\nangular momentum of cylindrical waves, we develop a design methodology for a\nbianisotropic cylindrical metasurface that enables perfect transformation of\ncylindrical waves. This formalism is applied to the acoustic scenario and the\nfirst experimental demonstration of perfect angular momentum transformation is\nshown.\n