论文标题
松弛的跨膜的拓扑过渡和表面umklapp散射
Topological transitions and surface umklapp scattering in Slack Metasurfaces
论文作者
论文摘要
地材和元面是波传播工程的巅峰之作，但迄今为止，他们的设计主要集中在深层波长的周期上，实际上形成了有效的介质。这样的方法忽略了重要的结构性自foredom，例如波纹周期性和深度之间的相互作用及其如何影响光束传输。在这里，我们提出了松弛的跨度 - 弱调制的金属 - 丝接口解锁了影响波传播的所有结构性自由度。我们在实验中证明了对此类跨面部表面波各向异性的控制，从而导致尚未探索的双阶段拓扑转换。我们进一步利用这些元信息来显示由umklapp过程驱动的表面波的独特向后聚焦 - 由结构的周期性性质增强的动量松弛。我们的发现可以应用于任何类型的引导波，引入了一种简单而多样的方法来控制人造媒体中的波浪传播。
Metamaterials and metasurfaces are at the pinnacle of wave propagation engineering, yet their design has thus far been mainly focused on deep-subwavelength periodicities, practically forming an effective medium. Such an approach overlooks important structural degrees-of-freedom, e.g. the interplay between the corrugation periodicity and depth and how it affects the beam transport. Here, we present Slack Metasurfaces - weakly modulated metal-dielectric interfaces unlocking all structural degrees-of-freedom that affect the wave propagation. We experimentally demonstrate control over the anisotropy of surface waves in such metasurfaces, leading to yet, unexplored, dual stage topological transitions. We further utilize these metasurfaces to show unique backward focusing of surface waves driven by an umklapp process - momentum relaxation empowered by the periodic nature of the structure. Our findings can be applied to any type of guided waves, introducing a simple and diverse method for controlling wave propagation in artificial media.
