Light-induced dynamics of metal aggregated nanoparticles

The light-induced forces in the aggregates of metal nanoparticles are studied with the Newton's and coupled dipole equations. The simulations imply a linear intrinsic optical response of the particles and host medium. Large and relatively fast third-order optical nonlinearity of such a nanocomposite is shown to originate from the light-induced motion of the particles. The nonlinear absorption coefficients of an artificial medium composed of 5-particles aggregates are simulated at different intensities and frequencies of the incident light. The calculated nonlinear absorption appears to be of the same order of magnitude as typically measured for the silver colloids.

[1]  G. Dietler,et al.  Force-distance curves by atomic force microscopy , 1999 .

[2]  F. Claro,et al.  Novel laser induced interaction profiles in clusters of mesoscopic particles , 1994 .

[3]  I. Mazets.  Polarization of two close metal spheres in an external homogeneous electric field , 2000 .

[4]  A. Campion,et al.  Surface-enhanced Raman scattering , 1998 .

[5]  V. P. Safonov,et al.  Nonlinear Optical Effects and Selective Photomodification of Colloidal Silver Aggregates , 2002 .

[6]  E. M. Lifshitz,et al.  Electrodynamics of continuous media , 1961 .

[7]  S. Rautian,et al.  A model of pair interactions in the theory of optical properties of fractal clusters , 2003 .

[8]  Vladimir P. Safonov,et al.  Polarization effects in nanoaggregates of silver caused by local and nonlocal nonlinear-optical responses , 2002 .

[9]  V. Shalaev.  Nonlinear Optics of Random Media: Fractal Composites and Metal-Dielectric Films , 1999 .

[10]  S. Rautian,et al.  On the theory of optical properties of fractal clusters , 2004 .

[11]  Vadim A. Markel.  Coupled-dipole Approach to Scattering of Light from a One-dimensional Periodic Dipole Structure , 1993 .

[12]  Vadim A. Markel.  Scattering of Light from Two Interacting Spherical Particles , 1992 .

[13]  Bruce T. Draine,et al.  The discrete-dipole approximation and its application to interstellar graphite grains , 1988 .

[14]  Vadim A. Markel,et al.  Small-particle composites. I. Linear optical properties. , 1996, Physical review. B, Condensed matter.

[15]  Vladimir P. Safonov,et al.  Surface-enhanced parametric scattering of light by silver clusters , 1988 .

[16]  Vladimir M. Shalaev,et al.  Saturation effect in the optical response of Ag-nanoparticle fractal aggregates , 2006 .

[17]  Vladimir P. Safonov,et al.  Giant nonlinear optical activity in an aggregated silver nanocomposite , 1998 .

[18]  Vladimir M. Shalaev,et al.  Fractals: giant impurity nonlinearities in optics of fractal clusters , 1988 .

[19]  Mark I. Stockman,et al.  Inhomogeneous eigenmode localization, chaos, and correlations in large disordered clusters , 1997 .