Abstract

Azimuthally polarized beams, focused by a high-numerical-aperture (NA) objective lens, form a hollow intensity distribution near the focus, which is appropriate for trapping low-refractive-index particles, in contrast to common linearly polarized or radially polarized beams. In this paper, the field distribution of the azimuthally polarized beam focused by a high-NA objective is described by the vectorial diffraction integral, and then the radiation forces on spherical particles with different parameters such as radius and refractive index are calculated by the T-matrix method. Numerical results show that the azimuthally polarized beam not only can steadily trap low-refractive-index particles at the focus center but also can trap multiple high-refractive-index particles around the focus center by virtue of the hollow-ring configuration. The range of the sizes of low-refractive-index particles that can be trapped steadily are presented, corresponding to different parameters such as the NA of the objective and the relative refractive index, based on which the NA of the objective can be selected to trap the appropriate size of particles.

© 2009 Optical Society of America

» View Full Text: Acrobat PDF (537 KB)

History
Original Manuscript: August 7, 2009
Manuscript Accepted: September 23, 2009
Revised Manuscript: September 19, 2009
Published: November 3, 2009

References

Please [login to View References]

Author Affiliations

Ming Lei

College of Life Science and Shaanxi Key Laboratory of Molecular Biology for Agriculture,Northwest Agriculture and Forestry University, Yangling 712100, China

Fei Peng, Baoli Yao, Shaohui Yan, Wei Zhao

State Key Laboratory of Transient Optics and Photonics,Xi'an Institute of Optics and Precision Mechanics, Xi'an 710119, China

Cited By

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

Advanced Search

Recent ToC Categories (Beta)

• Oct 08 2009 : See the latest ISP articles in the Applied Optics feature on Digital Holography in 3-D Imaging.
• Sep 25 2009 : Energy Express: Optics Express announces a special bi-monthly supplement dedicated to rapid developments in optics for sustainable energy.
• Sep 21 2009 : The 2009 Education and Training in Optics and Photonics papers are now available.

More News

• Invisibility Visualized
  Nov 12, 2009 - Scientists and curiosity seekers who want to know what a partially or... more
• Diamonds are a Laser's Best Friend
  Sep 18, 2009 - Tomorrow’s lasers may come with a bit of bling, thanks to a new... more
• Open Wide and Say ‘Zap’
  Aug 19, 2009 - A group of researchers in Australia and Taiwan has developed a new... more