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. (C) 2020 Optical Society of America