Fluctuational electrodynamics in the presence of finite thermal sources.
Fluctuational electrodynamics in the presence of finite thermal sources.
复制标题
有限热源存在下的脉动电动力学。
DOI：
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发表时间：
2007
影响因子：
8.6
通讯作者：
N. Vitanov
中科院分区：
文献类型：
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作者：
V. Yannopapas;N. Vitanov
我们给出了当球体的尺寸小于或相当于辐射波长时，黑体辐射的空间相关性的精确计算。通过超越标准的标量相干理论，我们证明了球面热源的空间关联函数不是普适的，而是依赖于热源的材料性质，并且表现出近场诱导的特征。近场效应也表现在介质球的线性链的情况下，其中关联函数探测链的不均匀性。对于后一种系统，我们建立了近场效应抵消和关联函数采用传统朗伯源的典型形式的条件。对于金属纳米球链的情况，远场的空间相关性增加导致定向热发射光谱。
We present exact calculations of the spatial correlation of the blackbody radiation in the presence of spheres whose dimensions are smaller or comparable to the radiation wavelength. By going beyond the standard scalar coherence theory, we show that the spatial correlation function of a spherical thermal source is not universal but depends on the material properties of the source and exhibits near-field-induced features. Near-field effects are also manifested in the case of a linear chain of dielectric spheres where the correlation function probes the inhomogeneity of the chain. For this latter system we have established the conditions when the near-field effects cancel out and the correlation function takes the typical form of a conventional Lambertian source. For the case of a chain of metallic nanospheres, the increased spatial correlation of the far field leads to a directional thermal emission spectrum.