Abstract
A gold plasmonic nanoantenna can provide additional local density of optical states (LDOS) for excited quantum emitters to radiative decay and thereby can shape the emission properties of the emitters. One example is the modulation of the antenna’s photoluminescence spectrum. Here, we fabricate gold nanoantennas with various size and study the modulation effect of gold nanoantennas systematically. All of the symmetry antennas show obvious modulation effects on the photoluminescence spectrum due to the transverse resonance, antibonding, higher-order and fundamental longitudinal localized surface plasmon resonance mode. The spectral features are in good agreement with that in the spectra obtained from dark-field scattering and numerical simulations. However, we have repeatedly observed extraordinary blue spectral shift for resonant modes between scattering and photoluminescence spectrum in symmetry antenna, but can’t observe in single nanorod. Our work shows that photoluminescence is strongly modulated by the LDOS of the nanoantennas and therefore can be used as a local luminescence source to report the LDOS.