含Ag量子点钠硼硅玻璃的三阶非线性光学性质

Third-order Nonlinear Optical Properties of Silver Quantum Dots Doped in Sodium Borosilicate Glass

以正硅酸乙酯、硼酸、金属钠为前驱体采用溶胶-凝胶法合成含 Ag 量子点的钠硼硅玻璃。X 射线粉末衍射（XRD） 分析 Ag 量子点具有立方相。通过透射电子显微镜 （TEM） 和高分辨透射电子显微镜 （HRTEM） 测定量子点的尺寸和分布, 结果显示在玻璃中量子点呈规则的球形, 并且尺寸在 5~13 nm 之间。紫外-可见（UV-Vis）吸收光谱仪得到 Ag 量子点的表面等离子体共振吸收峰大约在 406 nm 附近; 利用飞秒 Z-scan 技术在 800 nm 波长处用飞秒钛宝石激光辐照对 Ag 量子点玻璃的非线性光学性质进行研究, 该玻璃的非线性折射率 γ、 非线性吸收系数 β 和三阶非线性极化率 χ（3）分别为 –1.72×10-17m2/W, 9.96×10-11m/W, 1.01×10-11esu。

Silver quantum dots doped in sodium borosilicate glass were synthesized through Sol-Gel method using tetraethyl orthosilicate （TEOS）, boracic acid, metallic sodium as precursors. X-ray powder diffraction （XRD） analyses revealed that silver quantum dots were cubic crystalline phase; size and distribution of the quantum dots were meas- ured by transmission electron microscope （TEM） as well as high-resolution transmission electron microscope （HRTEM）. The results showed that spherical shape formed uniformly in the glass, and the size of these quantum dots ranged from 5 nm to 13 nm. Ultraviolet-visible （UV-Vis） absorption spectrometer obtained surface plasma resonance （SPR） absorption peaks as that of the Ag quantum dots at about 406 nm. Nonlinear optical properties of silver quantum dots doped glass were investigated by using Z-scan technique at the wavelength of 800 nm with femtosecond Ti＂ sap- phire laser radiation. The values of nonlinear refraction index γ nonlinear absorption coefficient β and the third-order nonlinear optical susceptibility χ（3） of the glass were estimated to be -1.72× 10^-17 m2/w, 9.96× 10^11 m/W, 1.01 × 10^11 esu, respectively.