Optical properties of a nanoegg–nanorod heterodimer: a quasi-static analysis

Abstract

Plasmon coupling between the dipolar localized surface plasmons of a nanoegg and the longitudinal dipolar localized surface plasmons of a nearby gold nanorod is investigated within a dipolar-quasistatic limit. This was achieved by varying the core-offset of the nanoegg for different nanorod sizes at a fixed coupling distance. With respect to the plasmon peaks of the isolated nanoegg, we studied blue shifted, resonant, and red shifted nanorods. We show that besides plasmon-induced resonance shifts, which occurred in all three cases studied, transparency dips are induced in both the absorption and scattering spectra of the nanoegg–nanorod dimer. The latter effect depends on the plasmon detuning frequency and the nanorod absorption cross section. In comparison to a nanoegg–nanosphere dimer, the optical properties of the nanoegg–nanorod dimer are more enhanced.