Hyper-Rayleigh and hyper-Raman scattering from silver nanoparticles trapped by a near-infrared laser beam
Hyper-Rayleigh and hyper-Raman scattering from silver nanoparticles trapped by a near-infrared laser beam
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DOI：
10.1117/12.614706
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发表时间：
2005-08
期刊：
影响因子：
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通讯作者：
H. Yoshikawa;Takashi Ihama;Tamitake Ito;Y. Ozaki;H. Masuhara
中科院分区：
文献类型：
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作者：
H. Yoshikawa;Takashi Ihama;Tamitake Ito;Y. Ozaki;H. Masuhara
当近红外激光聚焦在胶体银中时，不仅可以观察到银纳米颗粒的光学捕获，而且可以在激光焦点处观察到超瑞利散射。通过在胶体银中添加 NaCl 和罗丹明 6G，超瑞利散射得到增强，并且还观察到超拉曼散射。尽管连续激光照射，这些非线性光学响应仍表现出时间波动。实验结果表明，具有高非线性光学响应活性的聚集体被聚焦近红外激光捕获和/或产生。超拉曼信号的散射截面远低于普通拉曼散射，可以通过将 CW-YAG 激光聚焦在包括分析物的胶体银中轻松获得。事实证明，胶体银的光捕获是获得非线性光学响应的强大技术。
When near-infrared laser was focused in colloidal silver, not only optical trapping of silver nanoparticles, but also hyper-Rayleigh scattering were observed at the laser focus. By addition of NaCl and rhodamine 6G in the colloidal silver, hyper-Rayleigh scattering was enhanced and hyper-Raman scattering was also observed. These nonlinear optical responses showed temporal fluctuation in spite of the continuous laser irradiation. Experimental results suggested that aggregates which have a high activity for nonlinear optical responses were trapped and/or produced by a focusing near-infrared laser. Hyper-Raman signal, whose scattering cross section is much lower than normal Raman scattering, could be obtained easily by focusing a cw-YAG laser in colloidal silver including analytes. It was demonstrated that optical trapping of colloidal silver is a powerful technique to obtain the nonlinear optical responses.