Surface Plasmon Enhanced Heating of Gold Nanoparticles: A Plasmonic Optical Switch

Recent work by Lereu et al. (Appl. Phys. Lett. Vol. 86, 154101, 2005) demonstrates a method of all-optical transfer of modulation signals using surface plasmon excitation on thin gold films. Localized heating of the film, resulting from surface plasmon decay, alter the optical properties of the device. A similar optical modulation method is now presented using gold nanoparticles. Computational models are used to generate realistic values of the thermo-optical response of gold and the thermal dynamics of a hot nanoparticle-substrate device. Differential pump-probe reflectivity measurements were perferomed and demonstrate modulation frequencies of upto 10kHz, an improvement of two orders of magnitude over the thin-film device. Sample fabrication techniques using physical vapor deposition and interference lithography, and heat transport on the nanoscale are also discussed.