Band-pass plasmonic filter based on periodic cascade resonant cavities

A band-pass plasmonic filter based on periodic cascade resonant cavities is theoretically designed and analyzed. The transmission modes of surface plasmon polariton are well studied by the finite-difference time-domain method. The structure indicates the band-pass selection capability with several types of modes in the transmission spectra. The results show that the number of the transmission modes depends on the number of the cascade cavities period. These modes exhibit a shift with varying incident intensity involving Kerr medium in cascade cavities. The structure provides flexibility in design for pass-bands filter.