We report the observation of particles trapped at an air–water surface orbiting in a reverse direction with respect to the orbital angular momentum of the light field. The effect is explained by a combination of asymmetric particle shape and confinement of the particle on the 2D air–water interface. The experiment highlights the strong influence of the particle shape on the momentum transfer, an effect that is often not considered in optical trapping experiments.
© 2006 Optical Society of America
Atomic and Molecular Physics
Original Manuscript: June 13, 2006
Manuscript Accepted: July 7, 2006
Published: September 11, 2006
Vol. 1, Iss. 11 Virtual Journal for Biomedical Optics
A. Jesacher, S. Fürhapter, C. Maurer, S. Bernet, and M. Ritsch-Marte, "Reverse orbiting of microparticles in optical vortices," Opt. Lett. 31, 2824-2826 (2006)