Concentric layered Hermite scatterers
Concentric layered Hermite scatterers
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DOI：
10.1016/j.physleta.2018.03.041
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发表时间：
2018-05-31
影响因子：
2.6
通讯作者：
Parker, Kevin J.
中科院分区：
文献类型：
--
作者：
Astheimer, Jeffrey P.;Parker, Kevin J.
球散射的长波长限制在光学、电磁学和声学中有着丰富的历史。最近证明了一个公共积分核适用于声学和电磁两种情况下的弱球形散射体的公式。此外，当非均匀性具有符合高斯加权Hermite多项式的材料组成时，背散射振幅与波数k之间的幂律高于瑞利散射k(2)幂律。虽然这类散射体，称为埃尔米特散射体，是合理的，但制造由一层或多层包围的核心散射体可能更简单。在这种情况下，材料的非均匀性符合分段连续常数函数。通过考虑非齐次函数的矩及其空间变换，我们证明了这种情况下超瑞利散射幂律存在的充分必要条件。这一发展为构造和使用具有独特幂律行为的散射体开辟了一条新的途径。(C) 2018 Elsevier B.V.版权所有
The long wavelength limit of scattering from spheres has a rich history in optics, electromagnetics, and acoustics. Recently it was shown that a common integral kernel pertains to formulations of weak spherical scatterers in both acoustics and electromagnetic regimes. Furthermore, the relationship between backscattered amplitude and wavenumber k was shown to follow power laws higher than the Rayleigh scattering k(2) power law, when the inhomogeneity had a material composition that conformed to a Gaussian weighted Hermite polynomial. Although this class of scatterers, called Hermite scatterers, are plausible, it may be simpler to manufacture scatterers with a core surrounded by one or more layers. In this case the inhomogeneous material property conforms to a piecewise continuous constant function. We demonstrate that the necessary and sufficient conditions for supra-Rayleigh scattering power laws in this case can be stated simply by considering moments of the inhomogeneous function and its spatial transform. This development opens an additional path for construction of, and use of scatterers with unique power law behavior. (C) 2018 Elsevier B.V. All rights reserved.