Vol. 42, Issue 3, pp. 659-666 (2012)

Abstract

In the present paper, we have utilized Au nanoring arrays in an SiO₂ host to provide a T-structure for the purpose of routing and switching optical energy in optical integrated devices to operate at optical communication band (λ ≈ 1550 nm). To employ this router at spectral region considered, localized surface plasmons resonance (LSPR) must be red-shifted around 1550 nm. This T-shaped router includes Au nanorings with a 175 nm inner diameter, a 35 nm thickness and a 35 nm height, and the intercenter distance between two nanorings is 330 nm. To demonstrate the routing properties, we utilized the finite-difference time-domain (FDTD) method. It is shown that the non-straight chain can transport and route the optical energy with certain velocity of light and transmission coefficient. In addition, the percentage of transmitted or power ratio for this structure has been calculated as almost 90%. The optical energy transport can take place at group velocity of approximately 25% of the velocity of light (0.25c₀, where c₀ is the velocity of light in the vacuum). The router based on nanoring chains shows better performance in switching and transporting the optical energy in comparison to other nanoparticles (nanospheres, nanodisks and nanorods).