Acoustic oscillations of spherical metallic nanoparticles in dielectric media driven by ultrashort laser pulses

Abstract

A theory is developed for the acoustic oscillations of small-sized spherical metallic particles in a dielectric medium driven by ultrashort laser pulses. Analytic expressions are obtained for the amplitude and power of the longitudinal spherical acoustic oscillations as functions of the density and elastic properties of the medium, the laser pulse duration, electron temperature, particle radii, and electron-phonon coupling constant. The factors affecting the dynamics of the damping of the power of these waves are studied in detail and illustrated for the example of Au, Ag, and Cu particles embedded in a plexiglas matrix. © 2011 American Institute of Physics.