All-angle Negative Reflection with An Ultrathin Acoustic Gradient Metasurface: Floquet-Bloch Modes Perspective and Experimental Verification.

ABSTRACT: Metasurface with gradient phase response offers new alternative for steering the propagation of waves. Conventional Snell's law has been revised by taking the contribution of local phase gradient into account. However, the requirement of momentum matching along the metasurface sets its nontrivial beam manipulation functionality within a limited-angle incidence. In this work, we theoretically and experimentally demonstrate that the acoustic gradient metasurface supports the negative reflection for all-angle incidence. The mode expansion theory is developed to help understand how the gradient metasurface tailors the incident beams, and the all-angle negative reflection occurs when the first negative order Floquet-Bloch mode dominates inside the metasurface slab. The coiling-up space structur

SUBMITTER: Liu B 

PROVIDER: S-EPMC5653785 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature