首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 218 毫秒
1.
使用 5 32nm ,8ns激光脉冲研究了两种新型的基于富勒烯C6 0 结构体系的金纳米粒子合成物的光学非线性 .Z scan实验结果和理论分析的比较表明 ,材料的非线性吸收强烈地依赖于材料中的配合体 ,而非线性折射主要来自金纳米粒子的贡献 .而且与熟知的C6 0 甲苯溶液光限幅特性作了比较 ,分析了光限幅机理 .  相似文献   

2.
飞秒激光作用下金掺杂硅酸盐玻璃的光致晶化研究   总被引:4,自引:0,他引:4       下载免费PDF全文
研究了金掺杂硅酸盐玻璃在飞秒激光辐照和热处理作用下的光致晶化行为,分析探讨了其机理和激光辐照条件的影响.吸收光谱测试表明玻璃内部析出金纳米颗粒. 金纳米颗粒掺杂玻璃在近共振纳秒脉冲作用下显示了强的光限幅效应, 且改变飞秒激光诱导参数可改变该复合玻璃的光学非线性. 关键词: 光致晶化 飞秒激光 金纳米颗粒 硅酸盐玻璃 光限幅  相似文献   

3.
使用532nm,8ns激光脉冲研究了两种新型的基于富勒烯C60结构体系的金纳米粒子合成物的光学非线性.Z-scan实验结果和理论分析的比较表明,材料的非线性吸收强烈地依赖于材料中的配合体,而非线性折射主要来自金纳米粒子的贡献.而且与熟知的C60甲苯溶液光限幅特性作了比较,分析了光限幅机理. 关键词: 60结构体系')" href="#">基于富勒烯C60结构体系 金纳米粒子 等离子体 光限幅  相似文献   

4.
半导体中多光子吸收跃迁速率的全量子理论分析   总被引:3,自引:3,他引:0  
程昭  徐大纶 《光子学报》1992,21(1):1-10
本文从非线性光学中辐射跃迁速率的表达式出发,在全量子理论下,导出了半导体中任意阶多光子吸收跃迁速率的一般表达式。理论分析结果表明,n光子吸收跃迁速率与光强的n次方和n阶光子相干度成正比。本文在多能带及二能带理论模型下,对多光子吸收跃迁速率的一般表达式进行了化简,并对非线性相互作用项对跃迁速率的贡献,作了讨论。  相似文献   

5.
采用新型的热化学还原法,制备了银纳米颗粒掺杂的铋酸盐复合玻璃材料。利用紫外-可见吸收光谱观察到了银纳米颗粒表面等离子谐振(SPR)吸收的峰值位移特性,用拉曼光谱表征了引入银纳米颗粒后玻璃的结构变化。借助飞秒激光脉冲激发下的Z扫描与光克尔闸技术,在近红外波段下研究了材料的三阶非线性光学特性。研究结果表明银纳米颗粒铋酸盐复合材料有着亚皮秒级的非线性响应时间,并且其非线性折射率γ在纳米颗粒的热电子效应以及局部场效应的影响下,较基质玻璃最高可以提升29倍。  相似文献   

6.
根据紧束缚模型,利用格林函数的方法,将次近邻跃迁考虑在内,研究了扶手椅型石墨烯纳米带的输运性质.通过数值计算,给出了不同尺寸和不同次近邻跃迁能下系统的能量-电导和电流-电压特征曲线.结果表明,次近邻跃迁对扶手椅型石墨烯纳米带的输运性质有显著的影响.它破坏了电导共振峰关于能量的对称分布,增强了系统的导电性,减小了电子导电偏压阈值,加速了系统输运性能由半导体向导体转变. 次近邻跃迁能和石墨烯纳米带的尺寸越大,这种影响越明显  相似文献   

7.
激光诱导玻璃内部金纳米颗粒的析出及光谱   总被引:4,自引:0,他引:4  
使用钛宝石飞秒激光引发和热处理相结合,实现了在含有金离子的硅酸盐玻璃内部,有空间选择性地析出金纳米颗粒。对吸收光谱的研究表明,随着热处理温度的升高,吸收峰强度增大且红移;随着激光功率密度的增大,金纳米颗粒也增大。在特定的激光和热处理条件作用下,可以在玻璃内部有空间选择性的使金离子还原后聚集,形成金纳米颗粒,具有量子尺寸效应。改变激光功率和热处理温度可以控制所析出的金属纳米粒子的尺寸,从而实现多色显示,飞秒激光诱导金纳米颗粒具有稳定性,颜色具有持久性。  相似文献   

8.
TeO2-TiO2-Bi2O3系统玻璃的热学特性及光学带隙研究   总被引:4,自引:0,他引:4  
采用熔融淬冷法制备了系列高折射率的TeO2-TiO2-Bi2O3系统玻璃,测试了样品的密度、转变温度、析晶温度、折射率、吸收光谱,利用经典的Tauc方程计算了样品光学带隙允许的直接跃迁、允许的间接跃迁及Urbach能量.讨论了玻璃的热稳定性与组成之间的关系、研究了摩尔折射度、金属标准值、光学带隙、Urbach能量、Bi2O3和TiO2含量及光学碱度对玻璃样品折射率的影响.结果表明TeO2-TiO2-Bi2O3玻璃具有较好的热稳定性、样品的折射率随着摩尔折射度增大而增大,而光学带隙及金属标准值有减小的趋势,此外高的光学碱度对玻璃的高的三阶非线性也有一定的贡献.  相似文献   

9.
UTA模型下金M带谱的理论计算   总被引:2,自引:1,他引:1       下载免费PDF全文
 用不可分辩跃迁阵模型(UTA model)计算了金M带0.43nm~0.62nm范围含有的三十五个跃迁阵的特征参数。利用高斯分布线型,对每个离子谱依据UTA的总强度,对整个M带依据离子权重进行叠加,得到了在总体上与实验相一致的结果。  相似文献   

10.
郑立思  冯苗  詹红兵 《物理学报》2012,61(5):54212-054212
采用两相法分别制备一级硫醇修饰和二级十六烷基三甲基溴化铵(CTAB) 修饰的金纳米颗粒,通过透射电子显微镜和紫外-可见吸收光谱表征了其结构和线性光学性质. 采用开孔Z扫描技术,研究表面修饰对金纳米颗粒在532 nm波长激光作用下的非线性光学效应及光限幅性能的影响行为.结果表明,二级CTAB的修饰增强了颗粒在激光照射下的局域场作用, 并提高了热电子对非线性光学效应的贡献程度,从而有效地提高了金纳米颗粒的光限幅性能.  相似文献   

11.
Nonlinear optical characteristics of copper and silver nanoparticles in glass host matrices are studied by the Z-scan method at the wavelength of a Nd:YAG laser (λ=1064 nm) in a field of picosecond pulses. It is found that the third-order nonlinear susceptibility is more pronounced in glasses with copper nanoparticles than in glasses with silver nanoparticles. On the basis of experimental data obtained for samples with copper nanoparticles synthesized by ion implantation, it is shown for the first time that the nonlinear absorption of laser radiation with a wavelength lying out of the plasmon resonance region can be caused by a two-photon effect in metal particles. The character of the optical limiting process in the samples with copper nanoparticles when two-photon absorption is involved is discussed.  相似文献   

12.
We present rapid synthesis of gold nanoparticles by microwave irradiation method. Sample with average particle size 7.7 nm is obtained from TEM. Linear and nonlinear optical studies of the prepared samples are discussed. Reverse saturable absorption (RSA) at longitudinal surface plasmon resonance (SPR) in gold nanoparticles (Au NPs) have been observed using Z-scan and transient absorption techniques with 532 nm laser pulses. Such RSA behavior makes Au NPs an ideal candidate for optical limiting applications.  相似文献   

13.
Colloidal Au and colloidal Ag were prepared by chemical reaction method and the nonlinear optical properties of Au and Ag nanoparticles doped polyvinylpyrrolidone (PVP) composite films were investigated using Z-scan technique with 38 ps pulses at 532 nm. Open aperture Z-scan measurements indicated that both the Au/PVP and Ag/PVP composite films exhibited reverse saturable absorption. Nonlinear absorption coefficients and third-order nonlinear refractive indices were determined. The mechanisms accounting for the process of nonlinear refractions were analyzed and the figures of merit W and T of the Au/PVP and Ag/PVP composite films were evaluated.  相似文献   

14.
The study of the nonlinear optical parameters of suspensions and glass matrices doped with various nanoparticles (Ag, Cu, Co, Au, Pt, GaAs, CdS, As2S3) are presented. Various techniques for the preparation of nanoparticles in suspensions and solid matrices, in particular laser ablation, chemical methods, and ion implantation are discussed. We present our measurements of the nonlinear refractive indices, nonlinear absorption coefficients, saturation intensities, and nonlinear susceptibilities of nanoparticles-containing media using laser pulses generating in various spectral and temporal ranges. PACS 42.65.An; 42.65.Hw; 42.65.Jx; 61.46.Df; 78.67.Bf  相似文献   

15.
We present the results of studies of the nonlinear optical properties of Pd, Ru, and Au nanoparticles. We studied the nonlinear refraction and nonlinear absorption of suspensions of these nanoparticles at 1064-nm wavelength. A relatively strong nonlinear absorption of the Pd nanoparticles was observed in the case of 1064-nm, 50-ps pulses (β=2×10−9 m W−1). The Ru and Pd nanoparticles showed weak negative nonlinear refraction (γ∼−(6–8)×10−16 m2 W−1) in this spectral range. In the case of the Au nanoparticles, a saturated absorption at 532 nm dominated over other nonlinear optical processes.  相似文献   

16.
Au nanorods dispersed in aqueous solution were prepared with the electrochemical method. The absorption spectrum shows two absorption peaks corresponding to the perpendicular and transverse surface plasma resonance absorption of the nanorods. The third-order optical nonlinear properties are investigated by Z-scans. The signs of the nonlinear absorption coemcient and refractive index are reversed as the intensity of incident laser increases, which is due to the shape change of the gold nanoparticles melted by the intense laser pulses.  相似文献   

17.
李娆  朱亚彬  狄月  刘冬雪  李冰  钟韦 《物理学报》2013,62(19):198101-198101
采用纳米球刻蚀技术中漂移法在玻璃基片上制备较大 面积不同直径的聚苯乙烯小球掩模板, 采用磁控溅射技术在掩模板上沉积不同厚度的金薄膜, 去除聚苯乙烯小球后, 通过扫描电子显微镜观察到周期排列的三角状金纳米颗粒点阵. 通过紫外-可见分光光度计测试所制备样品的光吸收特性, 发现表面等离子体共振峰随粒径增大发生红移, 随金纳米颗粒高度增加发生蓝移. 基于Mie理论, 利用Matlab软件编程对不同粒径的金阵列光吸收特性进行理论模拟, 并与实验结果进行对比. 关键词: 纳米球刻蚀 金纳米颗粒阵列 表面等离子体共振  相似文献   

18.
Vanadium dioxide nanoparticles were synthesized in nanoporous silicate glasses with pore sizes of 7 and 17 nm. The temperature dependences of the optical and electrical properties of the composite obtained were studied near the temperature of the semiconductor-metal phase transition in vanadium dioxide. The non-linear optical response of the nanoparticles to picosecond laser pulses was studied in the visible and near-infrared ranges.  相似文献   

19.
采用正硅酸乙酯,硼酸,乙醇钠为先驱体,乙醇,乙二醇甲醚和乙醇为先驱体溶剂,并采用氯化金的水溶液为掺杂金微粒的先驱体,通过热处理使氯化金分解出金原子而使其长出金微粒,达到制备掺杂金微粒玻璃的目的。在钠硼硅系统干胶的制备过程中,详细地研究了氯化金的引入量等对大块干胶性质的影响,并确定了引入氯化金的适宜浓度。详细研究了干胶向玻璃转变的制备工艺,并成功地制备了掺杂金微粒的大块玻璃。采用X-射线衍射仪进行掺杂金微粒干胶和玻璃的桥晶与否分析,用紫外-可见吸收光谱研究了它们的光学性质。用透射电镜表征了金微粒在玻璃基质中的颗粒大小及分布,采用Z-Scan装置表征了此种玻璃的三阶非线性光学性质,得到折射率n2=8.22×10-12esu。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号