Nanoantenna-enhanced ultrafast nonlinear spectroscopy of a single gold nanoparticle

Supplementary Figure S1: Antenna enhancement for another antenna-particle pair: Same graph as in Fig.4 of the main text, but for another antenna-nanoparticle pair. The black curve shows the differential pump-probe spectrum of a single nanoparticle with 50 nm in diameter. As predicted this signal is stronger and also red shifted by about ∆λ = 20 nm compared to the single 40 nm nanoparticle shown in the main text. The red curve shows the signal strength of the nanoparticle in the coupled structure for a probe polarization along the symmetry axis. Again both effects of the antenna can be observed: we have a red shift of the whole signal onto the antenna’s resonance and also the expected enhancement, which amounts here to a factor of about 3.5.