Abstract

We study resonant self-action effects of light in plasmonic gamma-Fe2O3 (Au) core (shell) nanoparticles (NPs) in a polymer matrix by the spectroscopic Z-scan technique. Plasmon-assisted enhancement of the local optical field in NPs results in the appearance of saturable absorption, as well as in the amplification of nonlinear refraction by more than an order of magnitude compared with nonresonant conditions. (C) 2011 Optical Society of America