All-fiber polarization-dependent optical-vortex-controlling via acousto-optic interaction

The propagation of linearly polarized optical vortices of unit topological charge through circular optical fibers endowed with a propagating fundamental flexural acoustic wave is considered. A novel polarization-dependent optical vortex transformation is shown, in which the sign of the topological charge (and orbital angular momentum) of an outgoing vortex beam is determined by the direction of the incident linear polarization. This effect can be used for implementing a fast dynamic continuous control of both the orbital angular momentum and the intensity of outcoming vortex beams.