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. (c) 2008 American Institute of Physics.
Original language | English |
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Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 92 |
DOIs | |
Publication status | Published - 25 Feb 2008 |
Keywords
- EVANESCENT-WAVE ILLUMINATION
- TOTAL INTERNAL-REFLECTION
- 2-PHOTON FLUORESCENCE
- MICROSCOPY
- EXCITATION
- TWEEZERS
- FORCE