Song Hao, Hong Binbin, Qiu Yanbing, Yu Kuai, Pei Jihong, Wang Guo Ping
Opt Express. 2022 Jun 20;30(13):22885-22900. doi: 10.1364/OE.458971.
Functional tunability, environmental adaptability, and easy fabrication are highly desired properties in metasurfaces. Here we provide a tunable bilayer metasurface composed of two stacked identical dielectric magnetic mirrors. The magnetic mirrors are excited by the interaction between the interference of multipoles of each cylinder and the lattice resonance of the periodic array, which exhibits nonlocal electric field enhancement near the interface and high reflection. We achieve the reversible conversion between high reflection and high transmission by manipulating the interlayer coupling near the interface between the two magnetic mirrors. Controlling the interlayer spacing leads to the controllable interlayer coupling and scattering of meta-atom. The magnetic mirror effect boosts the interlayer coupling when the interlayer spacing is small. Furthermore, the high transmission of the bilayer metasurface has good robustness due to the meta-atom with interlayer coupling can maintain scattering suppression against positional perturbation. This work provides a straightforward method to design tunable metasurface and sheds new light on high-performance optical switches applied in communication and sensing.
功能可调性、环境适应性和易于制造是超表面中非常理想的特性。在这里，我们提供了一种由两个堆叠的相同介电磁镜组成的可调双层超表面。磁镜通过每个圆柱体的多极干涉与周期性阵列的晶格共振之间的相互作用而被激发，这在界面附近表现出非局部电场增强和高反射率。我们通过操纵两个磁镜之间界面附近的层间耦合，实现了高反射率和高透射率之间的可逆转换。控制层间距会导致可控的层间耦合和超原子的散射。当层间距较小时，磁镜效应会增强层间耦合。此外，双层超表面的高透射率具有良好的鲁棒性，因为具有层间耦合的超原子可以保持对位置扰动的散射抑制。这项工作提供了一种设计可调超表面的直接方法，并为应用于通信和传感的高性能光开关提供了新的思路。
