Multiband plasmonic filter based on double layer spoof surface plasmon polaritons

In this article, a multi-band plasmonic filter based on double layer spoof surface plasmon polaritons was presented. The multi-band performance resulted from the high-order modes of the spoof surface plasmon polaritons (SSPPs), which has been verified through the dispersion curves and surface electric fields. The cutoff frequency of each band of the filter corresponded to different order of modes of the asymptotic frequency of the SSPPs, which could be tuned by the depth of the groove at will. This simple multi-band plasmonic filter has potential applications in plasmonic circuits and systems.