Analysis of the Topological Charge by Focusing Vortex Beams with a Cylinder Lens

Vortex beams have special applications in many areas, such as quantum information processing, quantum entanglement, particles trapping and manipulation etc. A great deal of attention has been given to the research of the generating vortex beam and measuring the topological charge. This paper presents a method to measure the topological charge of vortex beams by using a cylinder Lens. Simulation and experiment results show that dark stripes appear when topological charge is non-zero, and the number of dark stripes is equal to the topological charge. Therefore our research results may be applied as a new method to analyze the topological charge of vortex beams.