Nanoplasmonic Loaded Slot Cavities for Wavelength Filtering and Demultiplexing

A class of nanoplasmonic loaded slot cavities composed of a silver nanorod placed in the center of a metal-insulator-metal slot cavity is introduced. Based on the nanocircuit concepts and transmission-line theory, a circuit model for the loaded structure is proposed. The numerical results together with the theoretical analysis show that the proposed nanostructure offers efficient tuning of the resonance wavelengths and their spectral separations, compared to a regular slot cavity. The findings pave the way for new designs and engineering of optical integrated circuits such as wavelength-selecting nanostructures with negligible crosstalk of the wavelength channels.