Tuning the optical absorption properties of Ag nanorods by their topologic shapes: A discrete dipole approximation calculation

Abstract

The optical extinction spectra of four topologically different Ag nanorod structures, needle, periodic, L, and Y shapes, have been calculated by the discrete dipole approximation. Both the needle and periodic shaped nanorods can be used to effectively tune plasmon resonant peaks, while the L- and Y-shaped nanorods influence the shape of the extinction spectra. This study shows that the topologic defects of nanorods have significant effects on the optical properties, and provides an alternative way to tune the plasmonic characteristics of metallic nanorods.