Nonlinear absorption and refractive index measurements of silver nanorods by the Z-scan technique

Abstract

The nonlinear absorption and refractive index of uniaxially-oriented, rod-type silver nanoparticles in longitudinal surface plasmon absorption region were measured by the Z-scan technique. A femtosecond mode-locked Ti:sapphire laser system operating at 800 kHz was used for the light source. Numerical analysis of the values obtained indicate that the third order optical nonlinearity of metal particles caused by the interband transition dominates, to the large extent, contribution due to the surface plasmon resonance.