Nonlinear-optical response of semiconductor nanoparticles with metallic shells at a wavelength of 1.06 μm

This paper presents the results of numerical modeling and an experimental study of the nonlinear-optical properties of optical composites with nanoparticles having a semiconductor core consisting of the oxide of a metal (Pb, Hg) and a metallic shell consisting of Ag. It is shown that, for a definite choice of the parameters of the nanostructure, its plasmon resonance shifts into the 0.8-1.1-mu m spectral interval. Saturation of the impurity absorption in the core of the nanostructure increases the amplitude of the plasmon resonance and limits the radiation at 1.06 mu m. Energy thresholds of the radiation limitation are experimentally obtained at 2 X 10(-7)-5 X 10(-5) J/cm(2) for nanosecond laser pulses. The extent to which the local field amplification and the scatter of the parameters of the nanostructures affect the nonlinear-optical response of the composite medium is considered. (C) 2008 Optical Society of America.