超常介质中光轴任意取向时电磁波传播的反常现象研究

Anomalous phenomena of electromagnetic wave propagation in metamaterials for arbitrary orientation of optical axis

当电磁波的传输轴和各向异性超常介质的光轴成任意夹角时,发现在界面处可以产生反常全向全反射和反常负折射现象.导出了电磁波的入射角和能流折射角之间的函数关系,根据此关系可方便地选择合适的介电张量和磁导率张量,使特定入射角所对应的折射是正或是负.此外,发现当入射角小于某一角度时,尤其在垂直入射附近时,透射率最小甚至为零;基于这一特性,提出了一种新型的薄片型高通空间滤波器的构想,和传统的空间滤波系统相比,可以大大减少滤波系统的体积;这一特性也可用于构造空间低频反射器件.

When there is an angle between the anisotropic metamaterials＇ optical axis and the electromagneticwave propagation axis,anomalous omnidirectional total reflection and anomalous negative refraction are discovered at the interface. The functional relation between incident angle and refractive angle of energy flow is obtained. According to this relation,we can restructure the refractive angle as negative or positive readily by selecting suitable permittivity and permeability tensors. And under these conditions,an anomalous transmittance emerges,such that when incident angle is less than a value,especially in the vicinity of vertical incident,the transmittance is minimum or even zero. According to these characteristics,a new slab spatial filter is put forward. Compared with the traditional space filter system,this new spatial filter＇s volume is smaller. And these characteristics can also be used to build a reflector of low spatial frequency.