Generation of vortex lightbeams

Generally, the vortex lightwaves are beams that propagates helically along an axis. In an optical vortex, light is twisted. Due to their twisting property, the light at the position of the axis cancels each other. If the vortex is projected onto a plane, its image looks like a halo, with a dark area without light in the middle. Vortex beams are a new type of laser beams, which have been widely used in optical micromanipulation, laser optics, bio-optics, optical information transmission, particle waveguide, atomic optics, and molecular optics. Compared to ordinary Gaussian beams, vortex beams have many advantages, such as: zero intensity at the center of the beam, cylindrical distribution of longitudinal light intensity, dark spot size on the order of micrometers, no heating effect, orbital angle momentum and so on. This makes the vortex beams have very high application value in many fields, such as optical capture, optical rotation, nonlinear optics, and optical information processing. The scientific value of the vortex beams is increasingly prominent. In this paper, a novel structure similar to a spiral phase plate(SPP) to generate a vortex beam is designed, and its intensity distribution is analyzed using simulation software, which can be seen as a combination of a lens and a spiral phase plate. We verify the feasibility of generating vortex beams by simulation analysis, and analyze vortex beams generated by the designed structure and the general spiral phase plate structure by simulation.