Generation of rotating intensity blades by superposing optical vortex beams

A kind of optical beam with controllable rotating intensity blades is generated by coaxially superposing two optical vortex beams with frequency difference (Δω), different topological charges (m1 and m2) and equal amplitude. It is shown theoretically that the number of the blades is determined by the subtraction of topological charges (m1 − m2) and the angular velocity of the rotating pattern is equal to Δω / (m1 − m2). In our experiment, the rotating beams were generated by two optical vortex beams with opposite topological charges, where the frequency difference is acquired by a rotating plate glass. The results are quite in accordance with the simulations.

► The rotation of superposed optical vortices with frequency differences is testified.
► Rotating characters of superposed LG beams are fully analyzed and tested.
► Subtractions of topological charges determine the shapes of rotating patterns.
► Angular velocity of pattern can be controlled by setting the frequency difference.