Liu Shenggang, Hu Min, Zhang Yaxin, Li Yuebao, Zhong Renbin
Terahertz Research Center, University of Electronic Science and Technology of China, Chengdu 610054, China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2009 Sep;80(3 Pt 2):036602. doi: 10.1103/PhysRevE.80.036602. Epub 2009 Sep 10.
This paper explores the physics of the electromagnetic diffraction radiation of a subwavelength holes array excited by a set of evanescent waves generated by a line charge of electron beam moving parallel to the array. Activated by a uniformly moving line charge, numerous physical phenomena occur such as the diffraction radiation on both sides of the array as well as the electromagnetic penetration or transmission below or above the cut-off through the holes. As a result the subwavelength holes array becomes a radiation array. Making use of the integral equation with relevant Green's functions, an analytical theory for such a radiation system is built up. The results of the numerical calculations based on the theory agree well with that obtained by the computer simulation. The relation among the effective surface plasmon wave, the electromagnetic penetration or transmission of the holes and the diffraction radiation is revealed. The energy dependence of and the influence of the hole thickness on the diffraction radiation and the electromagnetic penetration or transmission are investigated in detail. Therefore, a distinct diffraction radiation phenomenon is discovered.
本文探讨了由平行于亚波长孔阵列移动的电子束线电荷产生的一组倏逝波激发的亚波长孔阵列的电磁衍射辐射物理。由均匀移动的线电荷激活后，会出现许多物理现象，例如阵列两侧的衍射辐射以及通过孔在截止频率以下或以上的电磁穿透或透射。结果，亚波长孔阵列变成了一个辐射阵列。利用带有相关格林函数的积分方程，建立了这种辐射系统的解析理论。基于该理论的数值计算结果与计算机模拟结果吻合良好。揭示了有效表面等离子体波、孔的电磁穿透或透射与衍射辐射之间的关系。详细研究了能量依赖性以及孔厚度对衍射辐射和电磁穿透或透射的影响。因此，发现了一种独特的衍射辐射现象。
