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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
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Au-TiO2 composite films with Au atom content varying from about 15% to 82% are prepared by co-sputtering technique. Both open- and closed-aperture Z-scan of the samples are performed in the femtosecond time region. A conversion of the nonlinear absorption from negative to positive is observed as the A u atom content increases due to the saturation of reverse saturable absorption. The nonlinear refractive index γ and effective nonlinear absorption coefficient βeff at the Au atom content of 54% are measured to be 1.6 × 10^-2 cm^2/GW and -2.6 ×10^3 cm/GW, respectively. The corresponding third-order optical nonlinearity X^(3) is about 6.3 × 10^-8 esu. 相似文献
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在一台激光器和一个防震台的条件下,提出一种记录主全息图H1和彩虹全息图H2共用光路的实用设计布置方法。 相似文献
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等离激元共振能量转移指表面等离激元将俘获的能量通过偶极-偶极相互作用转移到邻近的半导体或分子等激子体系中,它是等离激元非辐射弛豫的一个通道,也可作为获取和利用等离激元共振能量的一种方式.此外,等离激元能量还可以通过热电子弛豫(非辐射)和光散射(辐射)等方式耗散.等离激元各个弛豫通道之间存在着很强的关联,相关的能量转移和电荷转移过程可以将等离激元耗散的能量输送到其他体系或转换为其他能量形式.本文主要介绍了等离激元共振能量转移和与其相关的能量和电荷转移过程(包括等离激元近场增强及耦合、远场散射、热电子弛豫等)的物理机制和动力学性质,并详细介绍了这些机制在增强光催化研究领域的最新进展. 相似文献
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提出了二维空间色彩编码透明片的一次曝光无狭缝真彩色彩虹全息的记录方法,并讨论了再现真彩色彩虹全息像的条件. 相似文献
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利用固相反应法制备了Sr14Cu24O41和Sr14(Cu0.99Zn0.01)24O41的样品,X-ray衍射分析显示,样品呈较纯的单相,样品的晶格常数掺杂前后并无明显变化.测量了S=0的非磁性元素Zn部分替代S=1/2的B位Cu离子后体系低温磁性质的变化.曲线整体拟合结果表明掺Zn使得体系中居里外斯部分的贡献减少,并且由Zn引入的局域磁矩通过近邻的自旋单态与次近邻的Cu2 进行超交换相互作用形成二聚体,使系统内二聚体的个数增加并且二聚体的耦合能减小. 相似文献
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We explore Nd3+ concentration and excitation power dependences of the avalanche upconversion of NdxY1-xVO4 (x=0-1) nanocrystals with uniform size and shape. The avalanche threshold power caused by the near-resonant energy transfer between 4F5/2→4I13/2 and 4F5/2→2G9/2 significantly decreases as the Nd3+ concentration increases. The off-resonant energy transfer between 4F5/2→4I13/2 and 4F5/2→4G11/2 in the strong excitation regime leads to apparent broadening on the blue-side of the upconversion spectrum of NdVO4 nanocrystals. 相似文献