Graded-index ridge surface plasmon polaritons waveguide

We propose and analyze a long-range dielectric-loaded surface plasmon polariton(SPP) waveguide based on graded-index ridge over server millimeter distances. Then the influence of the dielectric thickness and the ridge refractive index on propagation length and mode width is discussed and simulated with the finite element method. The result shows that the SPP can propagate as long as 3.42 mm, as well as the mode width keeping as 1.64 mm, a better one compared with the fixed refractive index. Considering its nanoscale dimension and outstanding performance, the structure is easily realized when connected with electrodes.