Anisotropic ɛ-near-zero effective medium multilayer structures for omnidirectional bending light to the normal are theoretically studied. A finite element method is presented, using a unit cell with Floquet port master and slave boundaries, for examining metal–dielectric multilayer structures to form the permittivity tensor. Ellipsometry measurements of CdO films are reported, and it is found that film thicknesses of ∼50 nm are adequate for the metallic layer. Omnidirectional bending to the normal is verified for multilayer structures, and this method is shown to simplify the computations over using a typical full space approach.

中文翻译：

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各向异性ɛ-接近零的多层结构，用于法向全向弯曲

各向异性ɛ为全向弯曲光到正常-near零有效介质的多层结构进行了理论研究。提出了一种有限元方法，该方法使用具有Floquet端口主边界和从边界的晶胞来检查金属-电介质多层结构以形成介电常数张量。报道了对CdO膜的椭偏测量，发现〜50nm的膜厚度对于金属层是足够的。已验证了多层结构向法线的全向弯曲，并且显示了这种方法比使用典型的全空间方法简化了计算。