Transition from out-of-plane to in-plane contribution for the optical second harmonicgeneration response from a silver metallic nanoparticle film

Abstract

The time evolution of the second harmonic generation (SHG) intensity during theformation of a silver spherical nanoparticle film at the water/1,2-dichloroethane interfaceis reported. The 5 nm diameter silver nanoparticles were initially dispersed inthe water phase and their precipitation at the interface was triggered with theaddition of sodium chloride. The time evolution of the SHG intensity exhibitedtwo distinct regimes. First, an intensity increase was observed during the filmformation with the deposition and the reorganization of the nanoparticles at theinterface. Then, a slow decrease of the intensity due to rearrangements withinthe film was observed. Polarization-resolved experiments were also performedand showed that the initial dominant out-of-plane contribution of the quadraticnonlinearity underwent a reorientational change towards a dominant in-planecontribution associated with a smoother but still discontinuous metallic film.