Kim Kihong, Lee D-H, Lim H
Division of Energy Systems Research, Ajou University, Suwon, Korea.
Opt Express. 2008 Oct 27;16(22):18505-13. doi: 10.1364/oe.16.018505.
We study the propagation of electromagnetic waves through a transition layer between positive-index and negative-index media theoretically. We consider three models where both the dielectric permittivity epsilon and the magnetic permeability micro change linearly from positive values to negative values. At the positions where epsilon or micro vanishes, the mode conversion of the incident electromagnetic waves into longitudinal plasma oscillations can occur. Using the invariant imbedding theory of mode conversion in inhomogeneous media, we calculate the mode conversion coefficient and the electromagnetic field profile in a numerically exact manner. We find that strong mode conversion can occur for both s- and p-polarized incident waves. The dependence of mode conversion on polarization is influenced very sensitively by the spatial profiles of epsilon and micro. We also discuss the interaction effects between mode conversion phenomena occurring at two resonance points located nearby.
我们从理论上研究了电磁波在正折射率和负折射率介质之间的过渡层中的传播。我们考虑了三种模型，其中介电常数ε和磁导率μ都从正值线性变化到负值。在ε或μ消失的位置，入射电磁波会发生向纵向等离子体振荡的模式转换。利用非均匀介质中模式转换的不变嵌入理论，我们以数值精确的方式计算了模式转换系数和电磁场分布。我们发现，对于s偏振和p偏振的入射波都会发生强烈的模式转换。模式转换对偏振的依赖性非常敏感地受到ε和μ的空间分布的影响。我们还讨论了在两个相邻共振点处发生的模式转换现象之间的相互作用效应。
