Optical trapping with a perfect vortex beam

Mingzhou Chen*, Michael Mazilu, Yoshihiko Arita, Ewan M. Wright, Kishan Dholakia

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

24 Citations (Scopus)
2 Downloads (Pure)


Vortex beams with different topological charge usually have different profiles and radii of peak intensity. This introduces a degree of complexity the fair study of the nature of optical OAM (orbital angular momentum). To avoid this, we introduced a new approach by creating a perfect vortex beam using an annular illuminating beam with a fixed intensity profile on an SLM that imposes a chosen topological charge. The radial intensity profile of such an experimentally created perfect vortex beam is independent to any given integer value of its topological charge. The well-defined OAM density in such a perfect vortex beam is probed by trapping microscope particles. The rotation rate of a trapped necklace of particles is measured for both integer and non-integer topological charge. Experimental results agree with the theoretical prediction. With the flexibility of our approach, local OAM density can be corrected in situ to overcome the problem of trapping the particle in the intensity hotspots. The correction of local OAM density in the perfect vortex beam therefore enables a single trapped particle to move along the vortex ring at a constant angular velocity that is independent of the azimuthal position. Due to its particular nature, the perfect vortex beam may be applied to other studies in optical trapping of particles, atoms or quantum gases.

Original languageEnglish
Title of host publicationOptical Trapping and Optical Micromanipulation XI
EditorsK Dholakia, GC Spalding
Place of PublicationBellingham
Number of pages5
Publication statusPublished - 16 Sept 2014
EventConference on Optical Trapping and Optical Micromanipulation XI - San Diego, Canada
Duration: 17 Aug 201421 Aug 2014

Publication series

NameProceedings of SPIE
ISSN (Print)0277-786X


ConferenceConference on Optical Trapping and Optical Micromanipulation XI


  • Optical Trapping
  • perfect vortex
  • Orbital Angular Momentum (OAM)
  • Orbital angular-momentum
  • Modes
  • Light


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