Atomic vortex beams in focal regions (4 pages)

Hong Yuan Ling, David E. Grochowski

Hui Zhai, Qi Zhou

Alon Luski

L. E. Helseth

We discuss some classes of atomic lenses capable of generating atomic vortex beams. For certain lens classes one may associate a topological charge with the beam in the focal region, and it is shown that an energy of the order $\ensuremath{\Elzxh}/\ensuremath{\tau}$ is needed to alter the topological charge by $\ensuremath{\Delta}n=\ifmmode\pm\else\textpm\fi{}1,$ where $\ensuremath{\tau}$ is the atom interaction time with the lens. We also find that the vortex can be manipulated by the properties of the atomic lens. In particular, it is suggested that the circulation varies locally in space.

Anatoly B. Kuklov, V. M. Kaurov

Francisco Misael Muñoz Pérez, Ferrando, Vicente, Walter D. Furlan +3 more

The design and implementation of a multiplexed spiral phase mask in an experimental optical tweezer setup are presented. This diffractive optical element allows the generation of multiple concentric vortex beams with independent topological charges. The generalization of the phase mask for multiple concentric vortices is also shown. The design for a phase mask of two multiplexed vortices with different topological charges is developed. We experimentally show the transfer of angular momentum to the optically trapped microparticles by enabling orbiting dynamics around the optical axis independently within each vortex. The angular velocity of the confined particles versus the optical power in the focal region is also discussed for different combinations of topological charges.