标题： 使用非局部超表面涂层的介质板宽角反射抑制 显示英文标题

标题： Wide-Angle Reflection Suppression of Dielectric Slabs Using Nonlocal Metasurface Coatings

摘要： 沿波传播路径的构成参数的不连续性会导致散射。 对于入射到平坦电介质板上的平面波，当电厚度较大时，反射强烈依赖于入射角。 这种行为限制了传统单层和多层抗反射涂层的适用性。 最近，受广义惠更斯条件的启发，通过局部响应的超表面实现的合成导纳片已被证明可以在宽入射角范围内消除电介质板的反射，然而，这种方法仅适用于光学薄板的情况。 在本工作中，我们研究了由两侧相同具有非局部响应的超表面覆盖的任意厚度电介质板的平面波传输，其网格阻抗具有角度依赖性（空间色散）。 非局部性被证明在光学厚板情况下实现宽角度反射抑制中起着关键作用。 为了验证我们的方法，我们研究了一种由互联的分裂环谐振器组成的超表面实现，该实现近似于预测的空间色散定律。 如数值和实验所示，这种精心设计的非局部超表面涂层确实能够在广泛的入射角度范围内提高厚电介质板的透射率（并抑制反射率），为光学薄且易于制造的抗反射涂层铺平了道路，这些涂层即使在光学厚电介质板的情况下也能在宽角度范围内高效工作。 显示英文摘要

摘要： Any discontinuity of constitutive parameters along a wave propagation path causes scattering. For a plane wave incident onto a flat dielectric slab, reflection becomes strongly dependent on the incident angle as the electrical thickness becomes large. This behavior limits the applicability of conventional single- and multilayer anti-reflective coatings. Recently, inspired by the generalized Huygens' condition, synthesized admittance sheets implemented as metasurfaces with local response have been shown to remove reflection from a dielectric slab in a wide range of incident angles, applicable, however, only in the case of small optical slab thickness. In this work, we study plane wave transmission through dielectric slabs with arbitrary thickness coated from both sides by identical metasurfaces with nonlocal response, whose grid impedance is angularly dependent (spatially dispersive). Nonlocality is shown to play a key role in obtaining wide-angle reflection suppression in the case of optically thick slabs. To validate our approach, we study a metasurface realization composed of Interconnected Split-Ring Resonators that approximates the predicted spatial dispersion law. As demonstrated numerically and experimentally, such properly devised nonlocal metasurface coatings indeed provide transmittance enhancement (and reflectance suppression) of thick dielectric slabs across a broad range of angles, paving the path to optically thin and easy-to-fabricate anti-reflective coatings efficiently operating in a wide angular range even for optically thick dielectric slabs.