Title: | Femtosecond Pulse-Width Dependent Trapping and Directional Ejection Dynamics of Dielectric Nanoparticles |
Authors: | Chiang, Wei-Yi Usman, Anwar Masuhara, Hiroshi 應用化學系 應用化學系分子科學碩博班 Department of Applied Chemistry Institute of Molecular science |
Issue Date: | 19-Sep-2013 |
Abstract: | We demonstrate that laser pulse duration, which determines its impulsive peak power, is an effective parameter to control the number of optically trapped dielectric nanoparticles, their ejections along the directions perpendicular to polarization vector, and their migration distances from the trapping site. This ability to controllably confine and eject the nanoparticle is explained by pulse width-dependent optical forces exerted on nanoparticles in the trapping site and ratio between the repulsive and attractive forces. We also show that the directional ejections occur only when the number of nanoparticles confined in the trapping site exceeds a definite threshold. We interpret our data by considering the formation of transient assembly of the optically confined nanoparticles, partial ejection of the assembly, and subsequent filling of the trapping site. The understanding of optical trapping and directional ejections by ultrashort laser pulses paves the way to optically controlled manipulation and sorting of nanoparticles. |
URI: | http://dx.doi.org/10.1021/jp404372a http://hdl.handle.net/11536/23542 |
ISSN: | 1932-7447 |
DOI: | 10.1021/jp404372a |
Journal: | JOURNAL OF PHYSICAL CHEMISTRY C |
Volume: | 117 |
Issue: | 37 |
Begin Page: | 19182 |
End Page: | 19188 |
Appears in Collections: | Articles |
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