Twin curvilinear vortex beams.

We report on a novel curvilinear optical vortex beam named twin curvilinear vortex beams (TCVBs) with intensity and phase distribution along a pair of two- or three-dimensional curves, both of which share the same shape and the same topological charge. The TCVBs also possess the character of perfect optical vortex, namely having a size independent of topological charge. We theoretically demonstrate that a TCVB rather than a single-curve vortex beam can be created by the Fourier transform of a cylindrically polarized beam. The behavior of TCVBs generated through our method is investigated by simulation and experiment, including interference experiments for identifying the vortex property of the TCVBs. The TCVBs may find applications in optical tweezers, such as trapping low refractive index particles in the dark region between two curves and driving them moving along the curvilinear trajectory.

Radially self-accelerating Stokes vortices in nondiffracting Bessel-Poincaré beams.

We theoretically propose and experimentally generate the nondiffracting Bessel-Poincaré beams whose Stokes vortices radially accelerate during propagation. To this end, we design the Bessel beams whose intensity is specified to be uniformly distributed along the longitudinal direction. By superposing two such Bessel beams having different helical phases and mutually orthogonal polarizations, the synthesized vector beam is endowed with the polarization singularity that can rotate about the optical axis, while the total intensities maintain their profiles. Radially self-accelerating Stokes vortices in the resulting beam can be manipulated by adjusting the predefined parameters in the constituent beams.