BaTiO3基Au纳米颗粒复合薄膜的制备及其光学性质研究

采用溶胶-凝胶(sol-gel)方法,成功的将高体积百分比的Au纳米颗粒复合到BaTiO₃的非晶薄膜中,并对其光学性质进行了研究.用XRD、TEM、椭偏仪、吸收光谱、光克尔效应0KE(Optical Kerr Effect)方法对薄膜进行了表征和测试.从吸收光谱观察到表面等离子体共振SPR(Surface Plasma Resonance)峰随热处理温度升高而红移的现象.光学非线性测试表明薄膜具有高的三阶非线性极化率x⁽³⁾和超快的响应时间.     

离子注入对聚对苯乙炔衍生物三阶非线性光学极化率的影响

利用能量为25keV，剂量为3．8×10^15-9．6×10^16ions／cm^2的氮正离子（N^＋）对聚（2，5-二己氧基）对苯乙炔（PDHOPV）薄膜进行注入改性研究。紫外-可见吸收光谱显示，注入离子在PDHOPV薄膜内部引入杂质能级，破坏分子的共轭结构，随着注入剂量增加，吸收边逐渐向长波方向移动，且分子激发态和基态间的光学禁带宽度由2．07eV减小至1．65eV。采用简并四波混频（DFWM）技术研究了离子注入对PDHOPV薄膜三阶非线性光学极化率的性能。结果表明，未注入薄膜的三阶非线性光学极化率（X^（3））为9．61×10^-10esu，随着注入剂量增加，X^（3）逐渐增大，当注入剂量达到3．8×10^16ions／cm^2。时，X^（3）值增加到最大值为8.44×10^-9esu。     

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.     

碲基复合材料薄膜的三阶非线性光学特性

采用电化学诱导溶胶-凝胶法在导电玻璃片上制备了具有三阶非线性光学特性的碲基复合薄膜材料. 采用SEM( 扫描电镜)和EDX( X 光电子能谱)对薄膜的表面形貌和组成进行表征; 应用分光光度计得到薄膜的透射光谱、反射光谱、吸收光谱, 并结合脉冲激光器和 Z 扫描方法测量薄膜的三阶非线性光学特性. 实验结果表明制备的薄膜呈网状结构, 表面组分主要包括Si、Te、O元素; 薄膜在波长为1064nm处呈现负的非线性折射效应和饱和吸收的性质, 其非线性折射系数和非线性吸收系数分别为-4.18×10 ^{- 13} m²/W和-1.6×10 ^{- 6} m/W, 表明了碲基复合薄膜有较强的非线性光学效应, 得到三阶极化率为1.13×10 ^{- 14} (m/V)², 表明复合薄膜具有优良的三阶非线性光学性能.     

Cd_2SnO_4等四种半导体薄膜制备及性能研究

采用喷涂热解法制备了以Cd2SnO4为代表的四种半导体薄膜，即Cd2SDO4，In2SnO5，TiSnO4及Zn2SnO4。测试了薄膜的半导体、光学和电学性能，得到了In2SnO5，Cd2SpO4薄膜电阻率的范围在10（－3）Ω·cm和高的透射比（可见光）；TiSnO4薄膜高的反射比（红外光）；同时，比较溅射法对结果进行了讨论。     

LaNiO3溅射薄膜的光学和电学特性的研究

采用LaNiO3陶瓷靶和射频磁控溅射技术在350℃的K9玻璃衬底上制备出了具有较好（100）择优取向的LaNiO3薄膜。通过对不同厚度薄膜的光学、电学以及薄膜结构等物理特性的测试分析，发现薄膜厚度小于100nm时为非晶结构，厚度大于150nm后出现了具有（100）择优取向的LaNiO3相。非晶结构的LaNiO3具有较高的面电阻和高的光学透射率，而晶化的LaNiO3薄膜具有类似于金属的导电能力和光学特性。薄膜的生长动力学和导电分析结果认为薄膜生长的初期会形成一个非晶过渡层。     

反应激光脉冲沉积法制备CoO和Co_3O_4薄膜

利用反应脉冲激光沉积法,以金属钴为靶材,通过改变衬底温度、反应气体氧气的流量等工艺参数,先后在玻璃衬底上成功制备了CoO薄膜以及Co3O4薄膜。通过X射线衍射（XRD）、X射线光电子能谱（XPS）、紫外-可见光吸收光谱（UV-Vis）研究了沉积工艺参数对沉积薄膜的晶体结构和光学特性的影响。结果表明,当氧气流量小于15sccm时,沉积的薄膜为岩盐矿结构的CoO,而当氧气流量大于15sccm时,沉积的薄膜为尖晶石矿结构的Co3O4。通过对紫外-可见吸收光谱的数据分析,证明CoO和Co3O4薄膜均为间接能带结构,禁带宽度分别为0.82eV和1.21eV。     

全氟羧酸离子交换膜内硫化铅超微粒的光学非线性研究

在全氟羧酸阳离子交换膜中制备出不同颗粒尺寸的ＰｂＳ超微粒，并由吸收光谱及电镜测量结果获得证实。用飞秒激光脉冲对ＰｂＳ超微粒复合膜进行了时间分辨光克尔效应测定，发现ＰｂＳ超微粒具有三阶光学非线性，三阶光学非线性极化率Ｘ（３）约为１０（－１２）ｅｓｕ，光克尔效应响应时间小于１６５ｆｓ，并且发现ＰｂＳ超微粒的光学非线性随着超微粒颗粒尺寸的减小而增大，显示出量子限域效应对于超微粒子光学非线性的贡献。     

PLT薄膜的制备及其非线性光学性能

用金属有机物热分解法制备了含镧ＰＬＴ薄膜，用Ｚ－ｓｃａｎ技术测试其非线性光学性能，结果表明；低镧的ＰＬＴ薄膜不显示非线性光学效应。高镧的ＰＬＴ薄膜非线性光学效应较强ＰＬＴ３０薄膜的非线性折射率高达０．３μｅｓｕ。     

有机／无机层状类钙钛矿（C12H25NH3）2PbI4晶体及薄膜的制备与结构表征

介绍了有机／无机类钙钛矿（C12H25NH3）2PbI4的晶体和薄膜的制备，并采用了XRD、SEM、AFM和PL表征材料的结构、形貌及光学特性等。XRD实验表明制备的（C12H25NH3）2PbI4晶体结晶度高。探索旋涂法制备工艺参数对薄膜结构的影响．在薄膜XRD中几乎只能观察到（0021）晶面的衍射峰．表明有机／无机类钙钛矿层沿平行与基片方向择优生长，SEM和AFM表明薄膜致密性较好，表面粗糙度较小。     

Optical nonlinearities of Au/TiO2 films excited by high-repetition-rate femtosecond laser

The Au/TiO₂ composite films have been fabricated using the pulsed laser deposition technique. The optical transmission spectra of the films were investigated in the range from 300 to 900 nm and the surface plasmon resonance peaks were observed varying from 550 nm to 650 nm. The optical nonlinearities of the as-deposited and annealed samples were investigated by the Z-scan method using a high-repetition-rate femtosecond laser. It was found that, for the as-deposited samples, the sign of nonlinear absorption coefficients (β) changed from negative to positive with increasing Au concentration. However, for all the annealed samples, the sign of β was found to be negative. The nonlinear responses induced by the cumulative thermal effects were suggested to contribute to this phenomenon.     

Bi2O3纳米晶玻璃三阶非线性光吸收性质的研究

利用溶胶凝胶法结合气氛控制方式合成了含Bi2O3纳米晶钠硼硅玻璃.利用X射线粉末衍射仪(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、X射线能量色散谱(EDX)、扫描模式透射电子显微镜(STEM)、高分辨透射电子显微镜(HRTEM)以及选区电子衍射(SAED)对掺杂在钠硼硅玻璃中Bi2O3纳米晶的形貌和微结构进行了表征,同时,利用飞秒开孔Z-scan技术详细地研究了Bi2O3纳米晶玻璃在800 nm处不同激发光强度下的三阶非线性光吸收性质.结果表明,在钠硼硅玻璃中形成了尺寸小于10 nm的Bi2O3单斜晶系纳米晶.随着激发光强度的增强,该玻璃的三阶非线性光吸收性质产生由饱和吸收向反饱和吸收的转变.进一步,计算得到的该玻璃三阶非线性极化率χ(3)的数量级范围在10-19~10-18m2/V2之间.这一结果说明该玻璃具有良好的非线性光学性能,并且在光限幅器等非线性光学领域具有潜在的应用价值.     

Nanocomposite thin films of Ga5Sb10Ge25Se60 chalcogenide glass for optical limiting applications

We report a low-cost, scalable method to fabricate optical grade composite thin films for nonlinear optical applications. The transmission and reflection spectra of prepared Ga₅Sb₁₀Ge₂₅Se₆₀/PVA composite films were investigated. Optical band gap of the thin films were calculated using Tauc’s extrapolation method. The band gap of the nanocomposite thin films were found to be tunable depending on the grain size of the films. Nonlinear optical characterization of samples were studied by the Z-scan technique using an Nd:YAG laser (532 nm, 7 ns, 10 Hz). Sequential Z-scan traces were made in four regimes of intensity for films with three different grain sizes. The Z-scan spectra reveal a strong nonlinear absorption depending on the grain size of the films suggesting that the new materials are promising candidates for the development of nonlinear optical devices and are extremely perspective as optical limiters of intense short pulse radiation.     

Optical nonlinearity and optical limiting of CdSeS/ZnS quantum dots

CdSeS/ZnS quantum dots (QDs) were synthesized through the chemical route. The optical limiting behavior of these QDs was observed. The quantum dots’ nonlinear absorption and nonlinear refraction were investigated by the Z-scan technique using a Nd:YAG laser second-harmonic radiation (λ = 532 nm, t = 35 ps). Based on the absorption and fluorescence spectra, it is reasonable for us to infer that the nonlinear absorption arises from free carrier absorption (FCA). These QDs have average absorption cross-section of 1.26 × 10^?16cm² and nonlinear refractive index in the order of 10^?8esu. The large nonlinear absorption perhaps allows them to be candidate material for the optical limiting devices.     

Effect of ingredient on optical properties of Ag/Cu metal alloy nanoclusters in silica glass

Formation of Ag-rich and Cu-rich Ag–Cu alloy nanoclusters in silica by Ag/Cu ion sequential implantation has been studied. The formation of alloy nanocluster has been evidenced by optical absorption spectra and transmission electron microscopy (TEM). Fast nonlinear refractive index and nonlinear absorption coefficient were measured at 790 nm of wavelength for Ag–Cu alloy nanocluster composites by the Z-scan technique. With different Ag/Cu ratio, linear absorption and nonlinear absorption are different in near infrared (NIR) region. It is suggested that by changing the ingredient percentage of metals in alloy, different optical nonlinearities could be selectively obtained.     

CsCl Effected Ultrafast Third-order Optical Nonlinearities of GeS_2-Sb_2S_3 Chalcogenide Glasses

A series of alkali halide doped chalcohalide glasses (100?x)(0.9GeS2-0.1Sb2S3)-xCsCl (x=5, 10, 15 and 20 mole fraction) were prepared. The absorption spectra and Raman scatting spectra of these glasses were measured. The optical band gaps Eopt were obtained from ultraviolet absorption edges. Z-scan technique was utilized to investigate the third-order nonlinear optical properties of GeS2-Sb2S3-CsCl glasses. The value of Eopt increases and the third-order optical nonlinearity decreases with increasing CsCl c...     

Optical bistability for ZnO–Nb2O5–TeO2 glasses

We examined the optical nonlinear properties of ZnO–Nb₂O₅–TeO₂. The absorption and Raman spectra were measured, the third-order nonlinear susceptibility was determined by degenerated four wave mixing technique. The magnitude of χ⁽³⁾ is about 1.0 × 10⁻¹² esu, larger than that of silica glasses, and the optical bistability was observed in a Fabry–Perot cavity.     

Gamma rays interactions with WO3-doped lead borate glasses

Optical and FT infrared spectral properties of tungsten ions in a host lead borate glass with composition PbO 55%, B₂O₃ 45% (wt%) were studied. The same spectral properties were re-measured after subjecting the samples to successive gamma irradiation. The work was undertaken to justify the state of tungsten ions in such glass system by combined spectral investigations. Optical and FTIR spectral studies were confirmed by investigating electron spin resonance (ESR) of the undoped and WO₃-doped samples before and after gamma irradiation. The optical spectrum of the undoped glass exhibits strong and wide UV absorption bands, which are related to the combined UV spectra of trace iron impurities (Fe³⁺ ions) and that from divalent lead (Pb²⁺) ions. Optical studies of WO₃-doped sample indicate the presence of tungsten ions mostly in the hexavalent W⁶⁺ state. The presence of tungsten ions as structural groups was obtained by comparing the FTIR spectra of the undoped and WO₃-doped samples. ESR spectra confirm the optical and FTIR spectral studies. The studied host lead borate glass has been found to show obvious shielding behavior towards successive gamma irradiation as revealed by the constancy of optical absorption spectral curves.     

新型PMMA/SiO_2/DR1非线性光学杂化材料的制备及表征

通过溶胶-凝胶法将硅烷染料DR1ASD、含硅氧烷PMMA和TEOS在酸催化条件下共水解-缩合制备了新型非线性光学杂化材料PMMA/SiO2/DR1,并运用FT-IR、SEM、UV-vis、DSC/TG和UV-vis等测试方法对其结构和性能进行表征.测试结果表明:杂化材料中有机相和无机相之间通过共价键结合,无相分离出现;杂化材料的玻璃化转变温度(Tg)和热分解温度(Td)分别达到165℃和405℃;电晕极化后杂化材料具有较高的生色团取向有序度(Φ=0.238),并表现出良好的取向稳定性,80℃条件下3h后依然有初始值的79%.