Regular Article

Study on orthogonal superposition generation method of double-ring vortex beams

¹ Faculty of Automation and Information Engineering, Xi’an University of Technology, Xi’an Shaanxi 710048, P.R. China
² Shaanxi Civil-Military Integration Key Laboratory of Intelligence Collaborative Networks, Xi’an 710126, P.R. China

^a e-mail: 867442855@qq.com

Received: 17 August 2019
Received in final form: 11 December 2019
Published online: 10 March 2020

Abstract

In the orbital angular momentum (OAM) multiplexing communication system, due to the orthogonality between OAM modes, two vortex beams with different topological charges are orthogonally superimposed to generate a double-ring vortex beam. The double-ring vortex beam generated by this method can ensure the independent propagation of information without interference. In this paper, the intensity and phase distributions of the double-ring vortex beam are theoretically analyzed and verified experimentally. The results show that the orthogonal superposition of any two vortex beams with different topological charges can generate the double-ring vortex beam. The distance between the double rings increases with the increase in the difference between the absolute values of the topological charges of two vortex beams. Using double-ring vortex beam to carry different information at the same time provides a new approach for improving channel capacity and transmission stability.