title: Surface plasmon assisted optical nonlinearities of uniformly oriented metal nano-ellipsoids in glass.
abstract: The nonlinear optical properties of nanocomposites consisting of non-spherical silver nanoparticles in glass matrix have been studied using the femtosecond Z-scan technique. The spheroidal nanoparticles were uniformly oriented along a common direction. By polarization sensitive studies, longitudinal and transverse plasmon resonances can be addressed separately. A sign reversal in optical nonlinearity from negative to positive is observed while switching the light interaction from near to non-resonant regime, which can be done by simply rotating the light polarization by 90°. Studying samples with different aspect ratio, we obtained the dispersion of third-order nonlinearity in the near-resonant regime, showing an enhancement of the nonlinear processes by more than two orders of magnitude due to the electric field enhancement at the surface plasmon resonance.
authors.affiliation: Physics Institute, Martin-Luther-University Halle-Wittenberg, D-06099 Halle, Germany.
authors.forename: Sabitha
authors.initials: S
authors.lastname: Mohan
authors.forename: Jens
authors.initials: J
authors.lastname: Lange
authors.forename: Heinrich
authors.initials: H
authors.lastname: Graener
authors.forename: Gerhard
authors.initials: G
authors.lastname: Seifert
mesh_terms: D005898:Glass / Q000737:chemistry*; D008027:Light; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D017711:Nonlinear Dynamics; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*