Design of flexural bottle beam metasurface with resonant pillar-type metamaterials

Abstract In this paper, we design a flexural metasurface capable of transforming plane or cylindrical waves into bottle shaped beam. The refractive index of the metasurface is calculated by Generalized Snell’s Law and discretized into 5 × 201 lattices, which is finally realized by resonant pillar-type unit cells. Simulation results demonstrate the bottle shaped focusing effect of the metasurface, which remains robust even in the presence of a scatterer inside the bottle beam. This work provides a theoretical and simulation foundation for the application and experiment of bottle beam in flexural wave control.