Dynamically controllable anisotropic metamaterials with simultaneous attenuation and amplification
Dynamically controllable anisotropic metamaterials with simultaneous attenuation and amplification
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DOI：
10.1103/physreva.92.053847
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发表时间：
2015-06
影响因子：
2.9
通讯作者：
T. Mackay;A. Lakhtakia
中科院分区：
文献类型：
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作者：
T. Mackay;A. Lakhtakia
经典电磁理论允许在特定频率下既不完全耗散又不完全活跃的各向异性均质超材料。完善的均质化形式表明，这种超材料可以很简单地实现为至少两种不同的各向同性介电材料的电小（可能是纳米级）球形颗粒的随机混合物，其中一种必须是耗散的，而另一种必须是活性的。这种超材料的介电性能受组成材料的体积分数、空间分布、颗粒形状和尺寸以及相对介电常数的影响。类似的具有更复杂的线性和非线性本构性质的超材料是可能的。活性组分材料的动态控制，例如通过受激拉曼散射，提供了超材料的动态控制。
Anisotropic homogeneous metamaterials that are neither wholly dissipative nor wholly active at a specific frequency are permitted by classical electromagnetic theory. Well-established homogenization formalisms indicate that such a metamaterial may be realized quite simply as a random mixture of electrically small (possibly nanoscale) spheroidal particles of at least two different isotropic dielectric materials, one of which must be dissipative but the other active. The dielectric properties of this metamaterial are influenced by the volume fraction, spatial distribution, particle shape and size, and the relative permittivities of the component materials. Similar metamaterials with more complicated linear as well as nonlinear constitutive properties are possible. Dynamic control of the active component material, for example via stimulated Raman scattering, affords dynamic control of the metamaterial.