Optical Magnus effect by transverse orbital momentum currents in reflection

The optical Magnus effect for vortex beam reflection at an air-glass interface is investigated. A vector field model to describe the rotation properties of vortex beam is established, which clearly shows that the orbital momentum currents of the beams lead to a rotation of their intensity pattern, quite different from the rotation properties in free space. Particularly, the circulation direction of orbital momentum currents is the same to the rotation direction of the beam centroid, and the circulation direction of orbital momentum currents are inverse for the incident and reflected beams. The rotation properties are topological-dependent, and the rotation angle of the beam centroid increases and the rotation velocity of the beam centroid decreases as the propagation distance increases.