Abstract:
We have measured the extinction spectra of colloidal solutions of gold nanoparticles synthesised by nanosecond laser ablation in water for the conditions of a bimodal particle size distribution. The extinction spectra are analysed by using the Mie theory and the contribution of particles of different sizes to the radiation attenuation is established. A method is proposed for determining the concentrations of individual populations of particles in a solution on the basis of the spectral dependence of the extinction coefficient. Mechanisms of the nanoparticle formation during laser ablation of metals in liquids are discussed.