Optical trapping of spheroidal particles in Gaussian beams

SH Simpson, S Hanna

Research output: Contribution to journalArticle (Academic Journal)peer-review

93 Citations (Scopus)


The T matrix method is used to compute equilibrium positions and orientations for spheroidal particles trapped in Gaussian light beams. It is observed that there is a qualitative difference between the behavior of prolate and oblate ellipsoids in linearly polarized Gaussian beams; the former generally orient with the symmetry axis parallel to the beam except at very small particle sizes, while the latter orient with the symmetry axis perpendicular to the beam. In the presence of a circularly polarized beam, it is demonstrated that oblate ellipsoids will experience a torque about the beam axis. However, for a limited range of particle sizes, where the particle dimensions are comparable with the beam waist, the particles are predicted to rotate in a sense counter to the sense of rotation of the circular polarization. This unusual prediction is discussed in some detail.
Translated title of the contributionOptical trapping of spheroidal particles in Gaussian beams
Original languageEnglish
Pages (from-to)430 - 443
Number of pages14
JournalJournal of the Optical Society of America A
Publication statusPublished - Feb 2007

Bibliographical note

Publisher: Optical Soc. of America


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