Polarization-resolved ultrafast dynamics of the complex polarizability in single gold nanoparticles.
Polarization-resolved ultrafast dynamics of the complex polarizability in single gold nanoparticles.
复制标题
单个金纳米颗粒中复杂极化率的偏振分辨超快动力学。
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
P. Borri
中科院分区：
文献类型：
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作者：
F. Masia;W. Langbein;P. Borri
利用外差探测中的相敏简并四波混频技术，我们在表面等离子体共振下测量了单个金纳米粒子的复极化率的超快变化。纳米粒子的非线性响应中的两个组件被区分，这取决于泵浦和探测脉冲的线性偏振方向和粒子的几何形状。一个组件被定量建模为由初始增加的电子气温度的泵脉冲的吸收后，以及随后的电子热化与晶格和周围引起的复介电常数的变化。测量的四波混频对探测场偏振方向的依赖性很好地再现包括偏离球形对称的纳米粒子介电常数。当探测场在泵浦-探测时间重叠处与泵浦场共极化时，第二个分量表现为测量的非线性显着增加。我们把这个分量的非线性响应相干表面等离子体移相到单电子激发之前。
Using a phase-sensitive degenerate four-wave mixing technique in heterodyne detection we measured the ultrafast changes of the complex polarizability in single gold nanoparticles at the surface plasmon resonance. Two components in the nanoparticle nonlinear response are distinguished, depending on the linear polarization direction of pump and probe pulses and particle geometry. One component is quantitatively modeled as the variation of the complex dielectric constant induced by the initial increase in the electron gas temperature following the absorption of the pump pulse, and the subsequent electron thermalization with the lattice and the surrounding. The dependence of the measured four-wave mixing on the probe field polarization direction is well reproduced by including a deviation from spherical symmetry in the nanoparticle dielectric constant. The second component manifests as a significant increase in the measured nonlinearity when the probe field is co-polarized with the pump field at pump-probe time overlap. We attribute this component to the nonlinear response from coherent surface plasmons before dephasing into single electron excitations.
影响因子：
10.8
作者：
Huang, Xiaohua;El-Sayed, Ivan H.;El-Sayed, Mostafa A.
通讯作者：
El-Sayed, Mostafa A.
影响因子：
3.6
作者：
Masia, Francesco;Langbein, Wolfgang;Borri, Paola
通讯作者：
Borri, Paola