Dielectric Nano-Systems with Unique Optical Properties

Abstract

The study of optical properties of Al2O3, SiO2, TiO2, and ZnO nanoparticles in weak optical fields is presented. We found that some nanoparticles have unique optical nonlinearity: The values of portions to nanoparticle refractive index and absorption coefficient increase to maxima, and then decrease to zero when the radiation intensity changes from 1 to 500 W/cm2. We estimated electron energy structures of nanoparticles and experimentally determined that such nonlinearity is directly related to peculiarities of the energy structure. We obtained a good fitting of theoretical results to the experimental ones (e.g. absorbance spectra of nanoparticles; the dependence of nanoparticle refractive index and absorption coefficient on radiation intensity).