title: Optimal annular computer-generated holograms for the generation of optical vortices.
abstract: We analyze a method for efficiently generating optical vortices by use of annular computer-generated holograms and a spatial light modulator. We found that there exists an optimal annular width by which the reconstructed vortex ring in the focal plane has the steepest gradient and the worthless subbright rings can be largely suppressed. We fitted a general formula for determining the value of this optimal annular width and propose a method for designing a multiring structure of optical vortices and specialized interferometric vortex patterns. Finally, we discuss the situation of a Gaussian beam as illuminated light and find that there exists an optimal beam waist that results in the best energy efficiency.
authors.affiliation: Department of Physics, Shandong Normal University, Jinan 250014, China.
authors.forename: Cheng-Shan
authors.initials: CS
authors.lastname: Guo
authors.forename: Xuan
authors.initials: X
authors.lastname: Liu
authors.forename: Xiu-Yun
authors.initials: XY
authors.lastname: Ren
authors.forename: Hui-Tian
authors.initials: HT
authors.lastname: Wang