title: Composite polarization singularities in superimposed Laguerre-Gaussian beams beyond the paraxial approximation.
abstract: The closed-form expression for the free-space propagation of superimposed Laguerre-Gaussian beams beyond the paraxial approximation is derived, and the composite polarization singularities formed by the transverse and longitudinal electric-field components are studied in detail. It is shown that there exist composite C-points and L-lines in vector nonparaxial fields. By suitably varying a control parameter, such as the off-axis distance, relative phase, or amplitude ratio, the motion, creation, and annihilation of composite C-points may appear, and in the process the sum of topological charge remains unchanged. The shift, deformation, combination, and disappearance of composite L-lines may take place. The topological relationship holds true. The results are compared with the previous work.
authors.affiliation: Department of Biomedical Engineering, Luzhou Medical College, Luzhou 646000, China. luoluoeryan@126.com
authors.forename: Yamei
authors.initials: Y
authors.lastname: Luo
authors.forename: Baida
authors.initials: B
authors.lastname: Lü
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008027:Light; D015233:Models, Statistical; D016011:Normal Distribution; D012031:Refractometry / Q000379:methods*; D012542:Scattering, Radiation