单轴各向异性左手材料的电磁特性

Electromagnetic characteristics of uniaxially anisotropic left-handed material

左手材料是近几年兴起的一种新型材料.以Maxwell方程为基础,通过理论计算,对光轴与界面成一定角度的单轴各向异性左手材料的一些电磁特性进行了研究.推导了这种材料中E偏振波和H偏振波的色散方程.对电磁波从各向同性右手材料入射到单轴各向异性左手材料时的折射和全反射现象进行了分析,得到了发生负折射和反常全反射的条件.推导了这种材料层的消逝波的反射系数和透射系数,发现当满足特定条件时,随着材料层厚度的增加,消逝波的透射率被指数倍放大.最后对这种材料层的偏振分束特性进行了研究,得到了实现偏振分束的条件.

Left-handed materials are a recent development. This paper studies some electromagnetic characteristics of uniaxially anisotropic left-handed materials according to the Maxwell equation. It gives theoretical calculations in which the optical axis was inclined with respect to the interface of the material. Disper- sion equations for E-polarized plane waves and H-polarized plane waves were derived. Refraction and total reflection were analyzed for the condition in which electromagnetic waves were incident from isotropic right-handed materials into uniaxially anisotropic left-handed materials, so that conditions of negative refraction and anomalous total reflection were obtained. The amplitude reflection coefficient and amplitude transmission coefficient were derived when evanescent waves passed through a slab of left-handed material. It was found that the transmissivity of evanescent waves is exponentially amplified as the thickness of the slab increases under certain special conditions. Finally, the polarized beam-splitting property of this material was examined, leading to a better understanding of conditions for polarized beam splitting.