Surface plasmon polariton based metal-insulator-metal filter including two face-to-face concentric semi-rings with different radii

摘要

The propagation characteristics of excited surface plasmon polaritons in a plasmonic filter are studied by controlling the geometric parameters of the waveguide. The proposed filter is composed of two nanoscale metal-insulator-metal type surface plasmon polariton based bus waveguides connected through two face-to-face concentric semi-rings with different radii placed at the top and bottom. Numerical results show that the wavelengths of the transmission spectra dips have changes of red shift when either the radius of the two semi-rings or the refractive index of the insulator is increased. This sensitivity is superior to the filter properties, and thus we believe that the proposed waveguide structure has potential application in nanoscale photonic devices integration. (C) 2017 Optical Society of America