Share Email Print

Proceedings Paper

Optical trapping, pulling, and Raman spectroscopy of airborne absorbing particles based on negative photophoretic force
Author(s): Gui-hua Chen; Lin He; Mu-ying Wu; Guang Yang; Y. Q. Li
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

Optical pulling is the attraction of objects back to the light source by the use of optically induced “negative forces”. The light-induced photophoretic force is generated by the momentum transfer between the heating particles and surrounding gas molecules and can be several orders of magnitude larger than the radiation force and gravitation force. Here, we demonstrate that micron-sized absorbing particles can be optically pulled and manipulated towards the light source over a long distance in air with a collimated Gaussian laser beam based on a negative photophoretic force. A variety of airborne absorbing particles can be pulled by this optical pipeline to the region where they are optically trapped with another focused laser beam and their chemical compositions are characterized with Raman spectroscopy. We found that micron-sized particles are pulled over a meter-scale distance in air with a pulling speed of 1-10 cm/s in the optical pulling pipeline and its speed can be controlled by changing the laser intensity. When an aerosol particle is optically trapped with a focused Gaussian beam, we measured its rotation motion around the laser propagation direction and measured its Raman spectroscopy for chemical identification by molecular fingerprints. The centripetal acceleration of the trapped particle as high as ~20 times the gravitational acceleration was observed. Optical pulling over large distances with lasers in combination with Raman spectroscopy opens up potential applications for the collection and identification of atmospheric particles.

Paper Details

Date Published: 25 August 2017
PDF: 7 pages
Proc. SPIE 10347, Optical Trapping and Optical Micromanipulation XIV, 103472A (25 August 2017); doi: 10.1117/12.2276972
Show Author Affiliations
Gui-hua Chen, Dongguan Univ. of Technology (China)
Lin He, Dongguan Univ. of Technology (China)
Mu-ying Wu, Dongguan Univ. of Technology (China)
Guang Yang, Dongguan Univ. of Technology (China)
Y. Q. Li, Dongguan Univ. of Technology (China)
East Carolina Univ. (United States)

Published in SPIE Proceedings Vol. 10347:
Optical Trapping and Optical Micromanipulation XIV
Kishan Dholakia; Gabriel C. Spalding, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?