Fibonacci vortex beam and its application in manipulating spiral transverse energy flow

The vortex beam carrying orbital angular momentum has attracted great attention because of its novel properties and various applications. For a traditional vortex beam, the phase changes along the azimuthal direction with the law of periodicity. As is known, besides the periodicity, the quasiperiodicity also draws interest, bringing inspiration to the area where the periodicity is applied. In this paper, we try to break the periodicity of the traditional vortex beam, and we propose a kind of Fibonacci vortex beam based on the Fibonacci sequence with quasiperiodicity. The Fibonacci vortex beam is generated in experiment, and the orbital angular momentum spectrum of the Fibonacci vortex beam is further analyzed. Subsequently, the focal property of the beam is investigated in detail. The transverse energy flow in the focal plane is with spiral distribution like a comet in a curved orbit, and it can transport particles to a specified location along a certain spiral path. The multiple Fibonacci vortex beam is further proposed to generate fan-blade-like transverse energy flow in the focal plane, which can be applied in attracting or sweeping particles with high efficiency. This work breaks the periodicity of the vortex beam, which is inspirational in studying the vortex beam and optical angular momentum, and it can also be applied in various areas such as optical trapping and manipulation.