Analysis of Plasmonic Waveguides and Gratings Using Implicit Finite-Difference Methods

[摘要] Various metal-insulator-metal- (MIM-) type plasmonic waveguides and gratings are investigated numerically. Three gratings are treated: one is formed by alternately stacking two kinds of MIM waveguides, another byperiodic changes in the dielectric insulator materials of an MIM waveguide, and the other by a periodic variation ofthe air core width in an MIM waveguide. The dispersion property of each MIM waveguide of which the grating consistsis analyzed using the implicit Yee-mesh-based beam-propagation method. It is shown that the third one hasa relatively large effective index modulation of the guided mode with a simple grating structure, while maintaining a low propagation loss. Further examination is given to modifications of this grating structure. The transmission characteristics are examined using the frequency-dependent implicit locally one-dimensional FDTD method. We discusshow the modified grating structure affects the bandgap of the transmission characteristics.

[学科分类] 电子、光学、磁材料