Berlin 2015 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 11: Ultrafast and Nonlinear Plasmonics

O 11.10: Vortrag

Montag, 16. März 2015, 17:15–17:30, MA 004

Nonlinear plasmonics of aluminum nanoantennas resonant at the second harmonic frequency — •Lili Gui, Jaco Fuchs, Bernd Metzger, Dominik Floess, Maxim Nesterov, and Harald Giessen — 4th Physics Institute and Research Center SCoPE, University of Stuttgart, 70569 Stuttgart, Germany

Localized surface plasmon resonances can boost significantly the optical nonlinearity of metallic nanoparticles due to the strongly confined and enhanced electromagnetic near-field. Although some double-resonant and multi-resonant configurations have been employed in order to achieve large nonlinear conversion efficiencies, there has been so far no quantitative investigation to illustrate the role of the plasmonic resonance of the nanoantenna at the harmonic frequency. It is still controversial whether the contribution of the harmonic resonance is adverse, as a loss mechanism due to more absorption, or beneficial, due to higher radiation efficiency.

Through comprehensive experimental studies of the second-harmonic spectroscopy of aluminum nanorods resonant at the second harmonic, we demonstrate that the contribution of the harmonic resonance is higher with regards to increased radiation efficiency than to increased absorption loss, with a clear evidence of larger overall second-harmonic-generation efficiency. The nonlinear response of the nanoantennas can be well explained by an analytic anharmonic oscillator model and nicely reproduced with finite-element simulations.