Chinese Optics Letters, 2021, Vol. 19, Issue 2, pp.
Estimating topological charge of propagating vortex from single-shot non-imaged speckle [Early Posting]
Chen Li, Kumar Singh Rakesh, Dogariu Aristide, Chen Ziyang, Pu Jixiong
- 华侨大学信息学院电子科学与技术系 光学与光子学研究所
Encoding information using the topological charge of vortex beams has been proposed for optical communications. The conservation of the topological charge on propagation and the detection of the topological charge by a receiver are significant in these applications and have been well established in free-space. However, when vortex beams enter a diffuser, the wavefront is distorted, leading to a challenge in the conservation and detection of the topological charge. Here, we present a technique to measure the topological charge of a vortex beam obscured in the randomly scattered light. The results of the numerical simulations and experiments are presented and are in good agreement. In particular, only a single-shot measurement is required to detect the topological charge of vortex beams, indicating that the method is applicable to a dynamic diffuser.