左手系材料对称平板结构中的波导模

Guided modes in a thin dielectric film symmetrically bounded by left-haned media

考虑由左手系材料作覆层衬底的对称波导系统,研究了TE线性极化波在该波导中的传播特性。利用直接图解法对各种波导模式进行了详细地判别,结果表明快波、慢波均可以在该波导中传播,两者的模式特征与传统介电波导及左手波导均存在较大差异。分析了导波的色散关系并定性地讨论了群速度随频率的变化规律。揭示了在一定条件下,该波导系统既可以支持前向线性TE波的传播也可以支持反向线性TE波的传播,且支持低阶陕波偶模式和慢波奇模式传播的频率段相对狭窄。

For linear TE electromagnetic plane waves propagating in a conventional waveguide bounded by symmetrical left-handed media, the guide modes are discussed in detail by looking for the intersections of curves, which are determined by the boundary conditions. The results prove that both fast waves and slow waves can propagate in this peculiar wavegui＇de system, and the relevant properties of the waves are quite different from which in conventional waveguide and left-handed waveguide. The frequency dispersion and group velocity are also considered. Base on the analysis, it can be concluded that this waveguide can support both forward linear TE waves and backward linear TE waves under certain conditions.