GeS_2-Ga_2S_3-AgCl微晶玻璃的制备及其光学性质

用熔融淬冷法制备了一系列GeS2-Ga2S3-AgCl三元系统硫卤玻璃。研究了样品的密度、热稳定性以及折射率随玻璃组分的变化规律。选取了75GeS2-10Ga2S3-15AgCl玻璃组分进行微晶化处理,并且在350℃下热处理得到了可见至红外透明的微晶玻璃样品。X射线衍射和扫描电子显微镜测试显示,玻璃中析出(Ga4Ge)S4和AgCl微晶相,晶粒尺寸为200～400nm。用Z扫描测量了微晶化前后玻璃样品在800nm波长下的三阶非线性特性,结果表明:在热处理后,玻璃的非线性折射率n2和非线性吸收系数β均明显增加,其中微晶玻璃的最大三阶非线性极化率χ(3)为8.619×10-11esu,是基质玻璃的2.2倍。     

几种卟啉衍生物及金属配合物的线性及三阶非线性光学性质

采用吸收光谱、荧光光谱和皮秒Z-扫描等实验方法研究了两种不同卟啉衍生物5,10,15,20-四苯基卟啉(TPPH2)、5,10,15,20-四对烯基苯基卟啉(T(4-VP)P)和一种金属卟啉配合物5,10,15,20-四苯基卟啉锌(ZnTPP)的线性及三阶非线性光学性质,并根据离域电子共轭结构理论和共振、非共振增强理论对结果进行了分析.     

纳米硅镶嵌氮化硅薄膜的制备及非线性光学性质研究

采用射频磁控反应溅射法结合热退火处理技术制备纳米硅镶嵌氮化硅(nc-Si/SiNx)复合薄膜.通过X射线能谱(EDS)、红外光谱(IR)、X射线衍射(XRD)及紫外-可见吸收光谱(UV-vis)的测定,对薄膜进行了组分、键合状态、结构及光学带隙的表征.采用皮秒激光运用单光束Z扫描技术开展了对该复合薄膜的非线性光学性质的研究,测得其三阶非线性折射率系数和非线性光吸收系数分别为10-8esu和10-8m/W量级,并将薄膜这种三阶光学非线性增强的原因归因于量子限域效应.     

Optical transition process in AgOx super-resolution near-field structure

A sandwiched 15 nm AgO_x thin film of the super‐resolution, near‐field optical disk was studied using a confocal Z‐scan system. Nonlinear optical properties of quartz glass/ZnS–SiO₂ (170 nm)/AgO_x (15 nm)/ZnS–SiO₂ (40 nm) were measured using a Q‐switch Nd : YAG pulse laser of wavelength 532 nm, pulse width 0.7 ns, and 15.79 kHz repetition rate. Transmittance and reflectance of the sandwiched AgO_x thin film show important optical responses at the focused position of Z‐scan. The dissociation processes of AgO_x, recombination of the silver and oxygen, and the resonance of the localized surface plasmon of the nano‐composites of the AgO_x thin film are correlated to transmittance and reflectance at the focused position of the Z‐scan for different input laser powers. An irreversible upper threshold intensity of 4.40 × 10⁶ mW cm^?2 at the focused position was found. A reversible working window of the focusing intensity between 1.86 × 10⁶ and 4.40 × 10⁶ mW cm^?2 was measured with sandwiched AgO_x thin film alone. The near‐field interactions of the AgO_x thin film and the recording layers of super‐resolution near‐field optical disk are also discussed.     

金纳米柱的可控制备及其光学非线性性质

以十六烷基三甲基溴化铵(CTAB)为表面活性剂,采用种子生长法,通过调节合成过程中反应物Ag NO3的加入量,改变生成物金纳米柱的长径比(σ)制备了一系列金纳米柱。利用SEM,TEM,UV-Vis等方法对金纳米柱试样进行了表征,并采用波长为532 nm的纳秒激光和皮秒激光对金纳米柱分别进行Z扫描测试其光学非线性性质。表征结果显示,随着σ的增加,其纵向的表面等离子体共振峰位红移,金纳米柱试样的σ和激发光的能量的不同直接影响其光学非线性性质;在纳秒激光的激发下,金纳米柱的光学非线性性质归因于表面等离子体吸收与非线性散射;而在皮秒激光激发下,其光学非线性性质则归因于基态等离子体的漂白作用。     

Thermal nonlinear refraction in the dye-doped sol–gel xTiO2 · (100 − x)SiO2 system

The build-up time of the thermal lens effect induced by a Gaussian beam in the DO3-doped sol–gel system xTiO₂ · (100 − x)SiO₂ at different compositions, both in the liquid and gel phases has been measured in a Z-scan geometry. While the pure titania samples show a minimum of the thermal diffusivity, a maximum is found for x ≈ 30. The sol to gel transformation leads to an increase of the build-up times at all compositions.     

Z—scan的理论及技术研究进展

本文在介绍传统Z－scan的基础上介绍双色光Z－scan（Tow color Z－scan）、双光束时间分辨率Z－scan（Time-resolved Z－scan）、遮挡Z－scan（Eclipsing Z－scan）、反向Z－scan（Reflection Z－scan）等改进的Z扫描技术。分析了各种Z－scan技术的特点及应用。综述了Z扫描理论与技术的发展。     

多孔硅1064nm波长处三阶非线性光学性质

采用日蚀型单光束扫描法测量了在不同孔隙率情况下,多孔硅薄膜在波长（ λ） 为１ ０６４ ｎ ｍ 处的非线性折射率。实验结果表明,孔隙率对多孔硅的非线性折射率影响较小。与单晶硅相比,多孔硅的三阶非线性光学效应没有得到很明显的增强。但在５３２ ｎ ｍ 波长处因诱导吸收引起了非线性折射率较强的增大     

测量光学非线性的Z扫描方法

本文从理论框架，测量灵敏度，光源，样品的吸收和厚度以及时间分辨等方面对光学非线性Z扫描测量方法的近年来的发展予以论述．