Analysis of the arm spacing effect on symmetric and asymmetric Y-shape optical power splitters: plasmonic interactions between gold nanorings.

In this paper, we investigated specific properties and features of several kinds of Y-splitters based on gold nanorings arrays which are surrounded by SiO2 host substance, to be used at C-band spectrum (γ ~ 1550 nm). The comparison between two kinds of splitters shows that the symmetric splitter demonstrates better performance than the asymmetric splitter at given wavelength with high efficiency and transmittance (power ratio). Calculations proved that the transmitted power percentage was approximately ~47.5% in the well-organized splitter. It is shown that the offset distance plays an important role in the quality of the optical energy division and transmission through the plasmonic waveguide. The influence of increasing and decreasing in the offset distance was demonstrated numerically by snapshots. Hence, choosing and determining the appropriate value for the offset distance lead to the structure with lower losses and higher percentage in energy transmission. Ultimately, the optical behavior of an asymmetric nanostructure with unequal distances between the arms and the main array is investigated and its applications and possible purposes are introduced. [ABSTRACT FROM AUTHOR]