Multi-resonant plasmonic transmission in a dual-periodically arranged metal-insulator-metal waveguide.

A metallic heterowaveguide array, which is alternatively stacked by two kinds of metal-insulator-metal waveguides in a dual-periodic arrangement, has been investigated numerically. Based on the transfer matrix method and the principle of plasmon Bragg reflector, multi-resonant surface plasmon modes with high quality factors have been predicted in the structure. The number of the resonant modes, the corresponding center wavelengths as well as the mode intervals can be controlled flexibly by adjusting the structure parameters. Numerical simulations performed by the finite element method show good agreement with the predication of the transfer matrix method. Our results could be applied for the future surface-plasmon based wavelength division multiplexers at the telecommunication band, multi-channel filters, and multi-wavelength light-emitting diodes.