The Periodically Graded Metal-Insulator-Metal Gap Structure for Plasmonic Waveguides.

In this paper, we explore the potential of the plasmonic metal-insulator-metal (MIM) periodically graded structure. Based on the coupled modes approach, an analytical model has been observed for the surface plasmon polariton (SPP) propagation. The band modes of SPP can be also supported by the MIM structure and we have analyzed the strong dependence of band width on structure parameters. The obtained analytical expressions allow one to easily choose the structure parameters for the desired band width. [ABSTRACT FROM AUTHOR]