Orbital-angular-momentum transfer to optically levitated microparticles in vacuum

arita2016pra_thumbnailMichael Mazilu, Yoshihiko Arita, Tom Vettenburg, Jaun M. Auñón Garcia, Ewan M. Wright, and Kishan Dholakia

Physical Review A 94, 053821 (2016)

doi: 10.1103/PhysRevA.94.053821

We demonstrate the transfer of orbital angular momentum to an optically levitated microparticle in vacuum. The microparticle is placed within a Laguerre-Gaussian beam and orbits the annular beam profile with increasing angular velocity as the air drag coefficient is reduced. We explore the particle dynamics as a function of the topological charge of the levitating beam. Our results reveal that there is a fundamental limit to the orbital angular momentum that may be transferred to a trapped particle, dependent upon the beam parameters and inertial forces present.