The electric and magnetic polarization singularities of Gaussian vortex beam in the free-space propagation

Abstract

Using the Fresnel vector diffraction integral and taking the Gaussian vortex beam as an example, the analytical expressions for the electric and magnetic components of Gaussian vortex beam propagating in the free-space are derived, and used to study the variations of electric and magnetic polarization singularities in free space. It is found that there exist two-dimensional (2D) and three-dimensional (3D) electric and magnetic polarization singularities in the free-space, which do not coincide in general. By varying waist width ratio, amplitude ratio, and propagation distance, the motion of polarization singularities takes place. In the 2D and the 3D electric and magnetic fields, the V-point may appear under a certain condition.