Au/SiO2 nanoring plasmon waveguides at optical communication band

We design and investigate plasmon waveguides based on linear arrays of An nanorings in an SiO2 host for use in an optical communication band (Delta similar to 1550 nm). Nanoring particles have better tunability and can achieve more laterally compact waveguides, compared to their solid counterparts, such as nanospheres and nanodisks. Three-dimensional simulations employing the finiite-difference time-domain algorithm are used to determine the set of geometrical parameters attaining localized surface plasmon resonance at 1550 mn. It is found out that, in the SiO2 host, Au nanorings attain LSPR at 1550 mn with a 175-nm inner diameter, a 35-nm height, and a 30-mn thickness. It is shown that linear chains of Au nanorings can transport the electromagnetic energy at 1550 nm, with transmission losses gamma(T) = 3 dB/655 mn and gamma(L) = 3 dB/443 nm and group velocities v(gT) = 0.177(c0) and v(gL) = 0.327(c0) for transverse and longitudinal polarizations, respectively, where c(0) is the speed of light in a vacuum.