Broad comparison between Au nanospheres, nanorods and nanorings as an S-bend plasmon waveguide at optical C-band spectrum

The integration of optical devices demands the fabrication of waveguides for electromagnetic energy below the diffraction limit of light. In this work, we have investigated the possibility of utilizing specific chains of closely spaced noble metal nanoparticles for waveguides beyond diffraction limit. Accordingly, we have employed Au and Ag nanorings in order to transport the optical energy through the plasmon waveguide at optical C-band spectrum (lambda approximate to 1550 nm). In proposed waveguides, we try to select the best structure via comparison between their transmission losses and group velocities of propagated energy. Three-dimensional simulations based on finite-difference time-domain algorithm (FDTD) are used to determine the related geometrical values. It is shown that nanoring's geometrical tunability and extra degree of freedom (DoFs) in its geometry can cause the optical energy to transport at 1550 nm with higher efficiency and lower losses in comparison with those of the other shapes of nanoparticles such as nanospheres and nanorods. (c) 2013 Optical Society of America.