C_(60)-TTF及Ru-oligothienylacetylide复合物的设计合成:新型非线性光诱导效应纳米材料(英文)

Nonlinear optics has been the subject of intensive research because of its wide applications in field of photonics, nanophotonics [1] and optoelectroncs such as optical signal processing, broad-band optical communications, integrated optics, optical sensing, optical poling, optical limiting, optical computing etc. A common problem in the laser technology is the protection of human eye and optical sensors from the damaging effects of high-energy light. Passive optical limiters can be the solution of this kind of problems.So optical materials with large coefficients of TPA and nonlinear refraction are of prime importance in optical limiting applications. Recently the C_ 60-TTF have attracted much attention because of their three-dimensional π-electron conjugated systems which makes them promising as new limiting materials [2]. Two-photon absorption, second harmonic generation (SHG), detection of phase transition using photoinduced nonlinear effects and illustration of new system for optical recording and erasing of holograms under weak laser illumination will be discussed. In other hand a series of new Donor-π-Acceptor ruthenium acetylide systems built around thiophene-based π-conjugating spacers has been developed and studied, in terms of the oligothienyl chain length. Comparison of the linear and third-order nonlinear optical properties of these Donor-π-Acceptor chromophores shows that the elongation of the spacer and introduction of a double bond in this spacer produces a considerable bathochromic shift of the absorption maximum together with a dramatic enhancement of the molecular cubic hyperpolarizability in these systems. Finally, acoustically induced second harmonic generation (AISHG) has been observed for thin films of these complexes incorporated in PMMA matrices, which reaches values among the highest, reported so far.

Influence of B_2O_3 on Spectroscopic Properties of Er^(3+)/Yb^(3+) Co-Doped Tungsten-Tellurite Glasses

A series of novel Er^3＋/Yb^3＋ co-doped （85- x ） TeO2-15WO3-xB2O3 （TWB;x=2%,5%,8%（mole fraction） ） glasses were prepared. Influence of B203 on the spectroscopic properties of Er^3＋/Yb^3＋ co-doped tungsten-tellurite glasses were investigated. It is found that the intensity of 1.5μm fluorescence, lifetime of the ^4I13/2 level and upconversion fluorescence all decrease with the increase of B2O3 content. The product of full width at half maximum （FWHM） and stimulated emission cross-section （σe^peak） of Er^3＋ ：^4I13/2→^4I15/2 transition has an optimum when B203 is 5% （mole fraction）. The emission spectra of Er^3＋ ： ^4I13/2→^4I15/2 transition was analyzed using peak-fit routine, and an equivalent four-level system was proposed to estimate the stark splitting for the 411512 and ^4I13/2 levels of Er^3＋ ions in TWB glasses at room temperature.

Epitaxial Growth of Gd_(0.67)Ca_(0.33)MnO_3 Thin Films by Laser Ablation

Gd_(0.67)Ca_(0.33)MnO_3(GCMO)thin films grown by laser ablation on SrTiO_3(100)(STO)substrates was studied. Films are highly crystallized, very well epitaxial and single-phased. The ordering magnetic temperature(T_c)of the films is much higher than the value of bulk samples of similar composition. It is found that the GCMO film exhibits a reversal of its magnetization at low temperature when cooled under a magnetic field. The negative magnetization is a consequence of the rapid increase(～1/T)with decreasing temperature of the magnetization of a sublattice aligned antiparallel to the local field, relative to the magnetic contribution of a second sublattice which is aligned parallel to the applied field.

Chalcogenide Glass for Passive Infrared Applications

Chalcogenide glass fibers have been successfully used for remote spectroscopy, temperature sensing and CO2 laser power delivery. In bulk form, chalcogenide glass is the most promising candidate for replacing the expensive germanium lenses for thermal imaging.

Improved Fluorescence from Tm^3＋/Er^3＋/Ce^3＋ Triply Doped Bismuth-Silicate Glasses for S＋C-bands Amplifiers

Fluorescence of Tm^3＋/Er^3＋ codoped bismuth-silica （BS） glasses and the sensitization of Ce^3＋ are investigated, It shows that Ce^3＋ codoping with Tm^3＋/Er^3＋ in BS glasses results in a quenching of Tm^3＋ ion emission from ^3F4 to the ^3H6 level. Consequently, the 1.47μm emission occurs after the population inversion between the ^3H4 and ^3F4 levels. Furthermore, the codoped glasses show the broad emission spectra over the whole S and C bands with full-width at half-maximum （FWHM） up to about 119nm, as it combines 1.55μm emission band of Er^3＋ with 1.47μm emission band of Tm^3＋ under 800hm excitation.

The Preparation and Photoluminescence Properties of Fluorosilicate Glass Ceramics Containing CeF3:Dy^(3+)Nanocrystals

Ce^(3+)and Dy^(3+)co-doped oxyfluoride glasses and glass ceramics containing CeF3 nanocrystals are prepared in a reducing atmosphere.XRD measurements and the calculated lattice parameters suggest that Dy^(3+)ions are incorporated with precipitated CeF3 nanocrystals along with a rise in the Dy^(3+)concentration or an increase in the annealing temperature.The glass ceramics emit white light close to the CIE coordinates of(0.3,0.3),derived from a combination of Ce^(3+)and Dy^(3+)emission.The CIE chromaticity coordinates of the Ce^(3+)and Dya+codoped glass ceramics can be tuned by varying the ratio of Ce^(3+)/Dy^(3+),while the luminescence intensity can be enhanced by heat treatment above 620℃.

White light generation of glass ceramics containing Ba_2LaF_7:Eu^(2+),Tb^(3+) and Sm^(3+) nanocrystals

The Eu 2＋ /Tb 3＋ /Sm 3＋ co-doped oxyfluoride glass ceramics containing Ba2LaF7 nanocrystals are prepared in the reducing atmosphere.The X-ray difiraction results show that Eu 2＋ ,Tb 3＋ and Sm 3＋ ions are enriched into the precipitated Ba2LaF7 nanophase after the annealing process.It deduces efficient energy transfers from Eu 2＋ to Tb 3＋ and Sm 3＋ and intenses warm white luminescence of the glass ceramics. Comparing with the glass,the luminescence quantum yield of the glass ceramics is also enlarged by about 3 times.This demonstrates the potential white light-emitting diode application of the glass ceramics produced in this letter.