A Plasmonic Triple-Wavelength Demultiplexing Structure Based on a MIM Waveguide With Side-Coupled Nanodisk Cavities

We propose and numerically investigate a plasmonic triple-wavelength demultiplexing structure based on metal-insulator-metal waveguides with side-coupled nanodisk cavities. The structure consists of three output channels, each of which is sandwiched by two nanodisk cavities and functions as a dual stop-band filter. The operation principle and transmission characteristics are analyzed by using the temporal coupled-mode theory and the finite-difference time-domain method. Simulation results show that the demultiplexed wavelength of each channel can be effectively tuned by adjusting the geometrical parameters of the structure. The proposed structure will find potential applications in photonic-integrated circuits and ultracompact optical communication systems.