Popa Bogdan-Ioan, Cummer Steven A
Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 Jan;73(1 Pt 2):016617. doi: 10.1103/PhysRevE.73.016617. Epub 2006 Jan 25.
Electric-field measurements inside a negative-permeability-positive-permittivity metamaterial composed of arrays of split-ring resonators directly show that the theoretically predicted enhancement of evanescent waves in passive materials is physically realizable. To circumvent the extreme sensitivity of this phenomenon to the material parameters, we show how the basic phenomenon occurs under relaxed conditions for a single transverse wave number and use this approach in our measurements. Measurements of the spatial distribution of the electric field in a three-slab configuration confirm that the evanescent wave enhancement responsible for the subwavelength focusing effect occurs in an electromagnetic material in a manner in close agreement with theory.
对由裂环谐振器阵列构成的负磁导率正电容率超材料内部的电场测量直接表明，无源材料中理论预测的倏逝波增强在物理上是可实现的。为规避该现象对材料参数的极端敏感性，我们展示了在单个横向波数的宽松条件下基本现象是如何发生的，并在测量中采用了这种方法。对三层结构中电场空间分布的测量证实，导致亚波长聚焦效应的倏逝波增强在电磁材料中发生的方式与理论非常吻合。
