A series of Ag/titanium oxide composite films with Ag atom concentration of 28%–82% were prepared by cosputtering technique. The scanning electron microscopy and the x-ray photoelectron spectroscopy studies reveal that metallic Ag nanoparticles with a size of 20–50nm disperse in titanium oxide. The plasmon resonance absorption peak of the embedded Ag nanoparticles shifts to about 860nm at Ag atom concentration of 42%, the nonlinear absorption coefficient βeff and the nonlinear refractive index γ are −1.4×105cm∕GW and 3.8cm2∕GW, respectively, which were measured by the Z-scan technique at 790nm with a peak irradiance of 1.8GW∕cm2. The corresponding third-order susceptibility χ(3) is about 4.7×10−7esu.

A series of ZnO microcrystallite films deposited on quartz substrates were annealed at the temperature of 600~1050 masculineC. A well c-axis grown wurtzite ZnO film was obtained at the annealing temperature of 850 masculineC. For the samples annealed above this temperature, the empirical parameter E(0) increased calculated from transmittance spectra, which indicated the changes of the interface of ZnO microcrystallite. Measured by Z-scans, the nonlinear absorption coefficient beta(eff) increased from 1.2x10(2) cm/GW to 1.1x10(3) cm/GW when the annealing temperature rose from 950 masculineC to 1050 masculineC, mainly due to the interfacial state enhancement.

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We report the spatial intensity distributions of the laser-induced charge and spin polarizations in GaAs∕AlGaAs two-dimensional electron gas (2DEG) detected by using second harmonic generation (SHG) imaging technique. The spin polarized electrons in the 2DEG are pumped by a single linear polarized laser beam and probed by another beam which produces reflective SHG. By comparing the images of SHG probed with left- and right-circular polarized laser beams, the spatial distributions of the effective charge and spin polarizations in the 2DEG sample are mapped out.