Arruda Tiago José, Martinez Alexandre Souto
Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, National Institute of Science and Technology in Complex Systems, Avenida Bandeirantes, 3900, 14040-901, Ribeirão Preto,São Paulo, Brazil.
J Opt Soc Am A Opt Image Sci Vis. 2010 Jul 1;27(7):1679-87. doi: 10.1364/JOSAA.27.001679.
We analytically calculate the time-averaged electromagnetic energy stored inside a nondispersive magnetic isotropic cylinder that is obliquely irradiated by an electromagnetic plane wave. An expression for the optical-absorption efficiency in terms of the magnetic internal coefficients is also obtained. In the low absorption limit, we derive a relation between the normalized internal energy and the optical-absorption efficiency that is not affected by the magnetism and the incidence angle. This relation, indeed, seems to be independent of the shape of the scatterer. This universal aspect of the internal energy is connected to the transport velocity and consequently to the diffusion coefficient in the multiple scattering regime. Magnetism favors high internal energy for low size parameter cylinders, which leads to a low diffusion coefficient for electromagnetic propagation in 2D random media.
我们通过解析计算了一个非色散磁各向同性圆柱体内部存储的时间平均电磁能量，该圆柱体受到电磁平面波的斜入射照射。还得到了一个用磁内部系数表示的光吸收效率表达式。在低吸收极限下，我们推导了归一化内能与光吸收效率之间的关系，该关系不受磁性和入射角的影响。实际上，这种关系似乎与散射体的形状无关。内能的这一普遍特性与传输速度相关，进而与多重散射 regime 中的扩散系数相关。对于小尺寸参数的圆柱体，磁性有利于高内能，这导致二维随机介质中电磁传播的扩散系数较低。
