A phase-only method is proposed to transform an optical vortex field into desired spiral diffraction-interference patterns.Double-ring phase apertures are designed to produce a concentric high-order vortex beam and a ...A phase-only method is proposed to transform an optical vortex field into desired spiral diffraction-interference patterns.Double-ring phase apertures are designed to produce a concentric high-order vortex beam and a zeroth-order vortex beam,and the diffracted intensity ratio of two beams is adjustable between 0 and 1.The coherent superposition of the two diffracted beams generates a brighter Airy spot(or Poisson spot)in the middle of the spiral pattern,where the singularity for typical vortex beam is located.Experiments employing circular,triangular,and rectangular phase apertures with topological charges from 3 to 16 demonstrate a stable,compact,and flexible apparatus for vortex beam conversion.By adjusting the parameters of the phase aperture,the proposed method can realize the optical Gaussian tweezer function and the optical vortex tweezer function simultaneously along the same axis or switch the experimental setup between the two functions.It also has potential applications in light communication through turbulent air by transmitting an orbital angular momentum-coded signal with a concentric beacon laser.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.T2293753 and T2293750)the Major Science and Technology Project in Hainan Province of China(Grant No.ZDKJ2019012).
文摘A phase-only method is proposed to transform an optical vortex field into desired spiral diffraction-interference patterns.Double-ring phase apertures are designed to produce a concentric high-order vortex beam and a zeroth-order vortex beam,and the diffracted intensity ratio of two beams is adjustable between 0 and 1.The coherent superposition of the two diffracted beams generates a brighter Airy spot(or Poisson spot)in the middle of the spiral pattern,where the singularity for typical vortex beam is located.Experiments employing circular,triangular,and rectangular phase apertures with topological charges from 3 to 16 demonstrate a stable,compact,and flexible apparatus for vortex beam conversion.By adjusting the parameters of the phase aperture,the proposed method can realize the optical Gaussian tweezer function and the optical vortex tweezer function simultaneously along the same axis or switch the experimental setup between the two functions.It also has potential applications in light communication through turbulent air by transmitting an orbital angular momentum-coded signal with a concentric beacon laser.
