Near-field optical trapping with an ultrashort pulsed laser beam

Author(s)

Kuriakose, Smitha; Morrish, Dru; Gan, Xiaosong; Chon, James W. M.; Dholakia, K.; Gu, Min

Available versions

Abstract

We report the focused evanescent optical trapping of nonfluorescent and fluorescent dielectric microspheres using a femtosecond laser. The experiment confirms that the trapping efficiency increases with the size of the particles. As a result, a pulsed laser has been used to trap particles in the Mie regime and to excite whispering gallery modes in them. The excitation of whispering gallery modes in a near-field femtosecond trap shows a significant suppression of the two-photon fluorescence background with an improvement of the photon storage factor by 46%, as compared to far-field two-photon excitation.

Publication year

2008

Publication type

Journal article

Source

Applied Physics Letters, Vol. 92, no. 8 (2008), article no. 081108

ISSN

0003-6951

Publisher

American Institute of Physics

Copyright

Copyright © 2008 American Institute of Physics. The published version is reproduced in accordance with the copyright policy of the publisher.

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