Xu Ji-Ren

OPTICAL PROPERTIES OF NANOMETER-SIZED CDO ORGANOSOL

In this paper, nanometer-sized CdO organosol was prepared by using microemulsion methods. Its electronic structure and optical properties are characterized through UV-visible light absorption, photoluminescence, and Z-scan techniques. Some new features were observed. Fluorescence and nonlinear optical responses are mainly related to surface trapped states.

Synthesis, structure, and optical properties of nanometer-sized In2O3 capped by anionic surfactant

In this article, nanometer-sized In2O3 organosol capped with a layer of anionic surfactants was prepared using microemulsion method. Its structure and optical properties were investigated through transmission electron microscopy, ultraviolet-visible absorption spectra, photoluminescence spectra and Z-scan technique. It was found that the prepared In2O3 organosol showed a series of new optical properties, which can be explained by its special oxygen vacancy structure. These new optical properties enhance its applications in information optics.

Reactive Sputter Deposition of Carbon Nitride Films by Using Hollow-Cathode Discharge

Carbon nitride films have been prepared by reactive sputtering using hollow cathode discharge. Auger spectra show that the nitrogen content is about 20-25 at.% in the bulk. Infrared (IR) spectra display three broad absorption bands. After heating treatment, changes of IR spectra suggest that the nitrogen incorporating in the bonding network of amorphous is thermally stable and hydrogen content decreases.

Spectroscopic investigation on the properties of visible and near infrared emissions in Tm3+, Ho3+ Co-doped YVO4 crystals

With the help of absorption and fluorescence spectra, the spectroscopic properties of Tm3+, Ho3+:YVO4 crystals have been investigated under different dopant concentrations. The absorption results show that the maximum absorption in the spectral range of currently available powerful laser diodes (LD) is at 796 nm, corresponding to the transition 3H6 → 3H4 of Tm3+ in the crystals. Upon the excitation with a LD at 808 nm, we have detected ten fluorescence bands in the spectral range spanning from visible to infrared. In visible region 4 upconversion bands have been observed centered at 475, 547, 660, and 701 nm. Discussions of the energy transfer processes suggest that cross relaxations and excited absorptions with the involvement of Tm3+ 3F4, 3H5 and Ho3+ 7I5 states are responsible for the four upconversion emissions. Comprising the relative integrated intersities of 2 µm (Ho3+: 5I7 → 5I8) and 1.8 µm (Tm3+: 3F4 → 3H6) bands we have observed an efficient energy transfer from Tm3+ (3F4) to Ho3+ (5I7). Examination of the ratios of the intensity of 2 µm band to that of 1.8 µm band as a function of the ratios of Tm3+ concentration (cTm) to Ho3+ concentration (cHo) indicates that small concentration ratios (cTm/cHo) lead to high efficient energy transfers of Tm3+(3F4) → Ho3+(5I7).

Nonresonant optical nonlinearities of surface chemically modified ZnO composite nanoparticles

With surface chemical modification, we have obtained core-shell structure ZnO nanoparticles. The nonresonant third-order nonlinear optical refraction of this new composite material was found to be -3.8 × 10-10 esu by Z-scan measurements with a femtosecond pulsed laser. The ultrafast nonlinear response time similar 250 fs measured by time-resolved pump-probe techniques suggests that the nonlinearity of this new material originates mainly from a rapid electronic polarization process or virtual process such as the optical Stark effect.

The linear and nonlinear optical properties of nanometer-sized In2O3 organosol

The linear and nonlinear optical properties of nanometer-sized In2O3 organosol were investigated by using TEM, ESR, UV-visible absorption spectrum, photoluminescence spectra and Z-scan technique. It was found that the prepared In2O3 organosol showed a series of new optical properties, which can be explained by its special structure. These new optical properties made its application in information optics enlarged.

Temporal evloution of the stark-broadening of Hβ line in laser-induced plasma in methane

The temporal evolution of stark-broadening of Hβ line in laser-induced plasma in methane is investigated and the electronic density is determined from the Stark-broadened linewidth of the Balmer beta line. The maximum half-width of the line is more than 100A and the deduced electronic density is about 4×1017 cm-3.