Efficient Optical Trapping of CdTe Quantum Dots by Femtosecond Laser Pulses

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• 作者：Wei-Yi Chiang ; Tomoki Okuhata ; Anwar Usman ; Naoto Tamai ; Hiroshi Masuhara
• 刊名：Journal of Physical Chemistry B
• 出版年：2014
• 出版时间：December 11, 2014
• 年：2014
• 卷：118
• 期：49
• 页码：14010-14016
• 全文大小：307K
• ISSN：1520-5207

文摘

The development in optical trapping and manipulation has been showing rapid progress, most of it is in the small particle sizes in nanometer scales, substituting the conventional continuous-wave lasers with high-repetition-rate ultrashort laser pulse train and nonlinear optical effects. Here, we evaluate two-photon absorption in optical trapping of 2.7 nm-sized CdTe quantum dots (QDs) with high-repetition-rate femtosecond pulse train by probing laser intensity dependence of both Rayleigh scattering image and the two-photon-induced luminescence spectrum of the optically trapped QDs. The Rayleigh scattering imaging indicates that the two-photon absorption (TPA) process enhances trapping ability of the QDs. Similarly, a nonlinear increase of the two-photon-induced luminescence with the incident laser intensity fairly indicates the existence of the TPA process.