混合型等离激元波导间隙区域模式场分布的近似理论计算

The Approximate Calculation of the Modal Field Inside the Gap of Hybrid Plasmonic Waveguides

混合型表面等离激元波导因其良好的波导性能得到广泛关注。该结构可以同时实现很长的传播距离和很强的亚波长约束。通过理论推导,结合镜像法和单步保角变换,给出了混合型表面等离激元波导间隙区域模式场的近似表达式。结果表明:近似解析表达式所得间隙区域模式场分布与数值计算结果符合得很好;提高折射率对比度近似解析结果将更精确。

Hybrid plapsmonic waveguides have attracted lots of research interest due to the high-performance in waveguiding,and can simultaneously achieve long propagation length and sub-wavelength confinement.Based on the theoretical derivation,the approximate expressions of the modal field inside the gap region of the hybrid plasmonic waveguide are given by combining the method of images and single-step conformal mapping.The results show that the model field distribution in the gap region obtained by the approximate analytical expression is in good agreement with the numerical results,and the approximate analytical results will be more accurate if the refractive index contrast is increased.