Experimental realization of an epsilon-near-zero metamaterial at visible wavelengths
Experimental realization of an epsilon-near-zero metamaterial at visible wavelengths
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DOI：
10.1038/nphoton.2013.256
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发表时间：
2013-11-01
期刊：
影响因子：
35
通讯作者：
Polman, Albert
中科院分区：
文献类型：
--
作者：
Maas, Ruben;Parsons, James;Polman, Albert
介电常数接近于零的光学材料具有独特的性质，即光的推进几乎没有相位推进。虽然这种材料已经在微波和远红外光谱范围内人工制造，但在可见光光谱范围内的大块三维epsilon-near-zero （ENZ）工程材料一直难以捉摸。在这里，我们提出了一种由精心雕刻的亚波长银和氮化硅纳米片平行阵列组成的光学超材料，其有效介电常数消失，如干涉测量所示。具有良好的阻抗匹配和光传输性能。ENZ条件可以通过改变几何形状在整个可见光谱范围内进行调节，并且可以实现新的微/纳米光学组件，例如透射增强、波前整形、可控自发发射和超辐射。
Optical materials with a dielectric constant near zero have the unique property that light advances with almost no phase advance. Although such materials have been made artificially in the microwave and far-infrared spectral range, bulk threedimensional epsilon-near-zero (ENZ) engineered materials in the visible spectral range have been elusive. Here, we present an optical metamaterial composed of a carefully sculpted parallel array of subwavelength silver and silicon nitride nanolamellae that shows a vanishing effective permittivity, as demonstrated by interferometry. Good impedance matching and high optical transmission are demonstrated. The ENZ condition can be tuned over the entire visible spectral range by varying the geometry, and may enable novel micro/nanooptical components, for example, transmission enhancement, wavefront shaping, controlled spontaneous emission and superradiance.