Measuring topology charge of vortex beam using digital holography

Abstract

In this paper we propose a method to detect the topology charge of vortex beam using digital holography. Hologram of vortex beam interference with reference beam is recorded, and the phase of vortex beam is reconstructed. The topology charge can be accurately determined by judging the periodicity of reconstructed phase distribution around the phase singularity. The phases of vortex beams generated by numerical simulation and those obtained by experiment of vortex beams with integral and fractional topology charges are compared with each other. The feasibility of the method of detecting the topology charge of vortex beam using digital holography is proved by comparing the results.