A nanometric plasmonic waveguide filter based on Fabry–Perot resonator

A compact nanometric surface plasmon polariton Fabry–Perot filter based on three metal-insulator-metal (MIM) waveguides is proposed and studied. The characteristics of this SPP band pass filter are analyzed by the finite difference time domain method and the Fabry–Perot resonance model. The results show that the resonance wavelengths of the pass bands can be linearly changed by the resonant cavity length, and the transmission ratios of the pass bands can be varied by altering the gaps between the MIM waveguides. The metal loss and dispersion effects on the SPP filter's spectra are considered as well. This kind of simple filter is very promising for high density SPP waveguide integrations.