OSA's Digital Library

Journal of the Optical Society of America A

Journal of the Optical Society of America A

| OPTICS, IMAGE SCIENCE, AND VISION

  • Editor: Stephen A. Burns
  • Vol. 26, Iss. 3 — Mar. 1, 2009
  • pp: 625–638

Optical angular momentum transfer by Laguerre–Gaussian beams

Stephen H. Simpson and Simon Hanna  »View Author Affiliations


JOSA A, Vol. 26, Issue 3, pp. 625-638 (2009)
http://dx.doi.org/10.1364/JOSAA.26.000625


View Full Text Article

Enhanced HTML    Acrobat PDF (354 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations

Abstract

It is well known that Laguerre–Gaussian beams carry angular momentum and that this angular momentum has a mechanical effect when such beams are incident on particles whose refractive indices differ from those of the background medium. Under conditions of tight focusing, intensity gradients arise that are sufficiently large to trap micrometer-sized particles, permitting these mechanical effects to be observed directly. In particular, when the particles are spherical and absorbing, they rotate steadily at a rate that is directly proportional to the theoretical angular momentum flux of the incident beam. We note that this behavior is peculiar to absorbing spheres. For arbitrary, axially placed particles the induced torque for rotation angle ζ is shown to be Γ z = A sin ( 2 ζ + δ ) + B , where A, B, and δ are constants that are determined by the mechanisms coupling optical and mechanical angular momentum. The resulting behavior need not be directly related to the total angular momentum in the beam but can, nonetheless, be understood in terms of an appropriate torque density. This observation is illustrated by calculations of the torque induced in optically and geometrically anisotropic particles using a T-matrix approach.

© 2009 Optical Society of America

OCIS Codes
(290.4020) Scattering : Mie theory
(050.1755) Diffraction and gratings : Computational electromagnetic methods
(350.4855) Other areas of optics : Optical tweezers or optical manipulation
(050.4865) Diffraction and gratings : Optical vortices

ToC Category:
Diffraction and Gratings

History
Original Manuscript: November 7, 2008
Revised Manuscript: January 8, 2009
Manuscript Accepted: January 13, 2009
Published: February 24, 2009

Virtual Issues
Vol. 4, Iss. 5 Virtual Journal for Biomedical Optics

Citation
Stephen H. Simpson and Simon Hanna, "Optical angular momentum transfer by Laguerre-Gaussian beams," J. Opt. Soc. Am. A 26, 625-638 (2009)
http://www.opticsinfobase.org/josaa/abstract.cfm?URI=josaa-26-3-625

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited