Abstract

We report the study of the nonlinear response of a composite material consisting of elongated silver nanoparticles that are aligned in a preferencial direction. The nanoparticles are contained in a thin layer embeded in a silica host. The absorptive and refractive contributions to the nonlinearity response of the sample were studied using the z-scan technique with 80 fs pulses at 825 nm. The nonlinear response was studied as a function of the intensity, and the polarization angle of the light. A large anisotropy was observed in both the refractive and absorptive contributions to the nonlinearity. The fast electronic and slow thermal contributions to the nonlinear response were resolved by conducting experiments using a chopper to change the thermal load to the sample, while mantaining a constant peak irradiance.

© 2013 Optical Society of America