单负材料对平板波导的模式影响

研究了内包层为负ε材料（ENG）的对称5层平板波导的传输特性。研究表明,这种波导既支持振荡导模（所有TE模和m〉0的TMm模）的传播,又支持TM0,TM1模的表面波传输。在波导中可传输的TM模的模式数目比TE模多1支,同阶的TM模的有效折射率高于TE模。随着ENG层厚度的增加,振荡导模的有效折射率范围扩大。ENG层厚度达到一定后,对波导的传播模式的影响可以忽略。随着芯层厚度的减少,波导中可传输的模式数越来越少。芯层厚度达到一定程度后,就可以在波导中实现单模传输。

Effect of Single-Negative Materials on the Slab Waveguide Modes

Propagation characteristics of symmetrical five-layer slab waveguide with epsilon-negative material（ENG） in inner clad have been studied.It is demonstrated that this waveguide not only supports the propagation of oscillating guided mode of all the TE modes and TMm modes for m0,but also supports the surface wave transmission of TM0 and TM1 mode.The number of TM modes is more than that of TE modes by one,and the effective refractive index of the same order is also larger.With the thickness of ENG layer increasing,the effective refractive index range of the oscillating guided mode expands.When the thickness of ENG layer reaches a certain value,its effect on the guided modes can be neglected.If the thickness of the core layer decreases,the number of guided modes will also decrease.Under certain condition,we can achieve a single-mode waveguide.