Creating and probing of a perfect vortex in situ with an optically trapped particle

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

Optical Review 22(1), 162-165 (2015)

doi: 10.1007/s10043-015-0031-7

We experimentally create a ‘perfect’ vortex beam, which has a uniform ring profile and fixed radius. In contrast with other vortex fields, the intensity profile is independent of its topological charge. We then correct this field in situ using a single trapped particle as a probe. This results in a constant angular velocity for the particle regardless of its position on the beam circumference.