Propagation Characteristic of Symmetric Airy Vortex Beams

A symmetric Airy vortex beam can be generated by modulating a Gaussian beam imposed on an improved phase pattern, where helical phase factor is introduced in symmetric cubic phase. The experimental results and numerical simulations demonstrate that such beams possess autofocusing characteristic and have a dark core owing to on-axis vortex. Such a special structure causes the beams to rotate in the initial plane. The lager topological charge, the bigger dark area, the greater rotating angle. The positive or negative topological charge only changes the rotating direction. Theoretical analysis shows that in the initial plane, the main lobe of symmetric Airy beams and off-axis vortex have nearly no influence. However, off-axis vortex will gradually appear on one of the main lobes of the symmetric Airy beams during propagation. In addition, the symmetric Airy beams also can embed multiple off-axis vortices which can capture multiple particles without damage. Due to the above characteristics, the beams have potential applications in optical trapping and biomedicine.