Femtosecond active plasmonics: ultrafast control of surface plasmon propagation

Abstract

Excitation of an aluminium/dielectric plasmonic waveguide with 200 fs optical pulses leads to the transient modulation of surface plasmon-polariton signals propagating in the waveguide. We show that by tuning the excitation wavelength to aluminium's interband absorption peak at ∼1.5 eV, a modulation depth of more than 35% can be achieved at an excitation fluence of 13 mJ cm−2. 'Fast' (femtosecond) and 'slow' (picosecond) modulation response components