A distributed reception-based method for identifying vortex beams

After the vortex beam is transmitted in the space laser communication scene for thousands or even tens of thousands of kilometers, the spot diameter will expand to several meters or even tens of meters, and the existing detection methods that require receiving the whole spot are no longer applicable. To address this problem, this paper proposes a distributed detection scheme to identify the topological charge of the vortex beam by analyzing and processing the data received from each detector. Matlab is used to simulate the proposed scheme. The vortex beam is a Laguerre-Gaussian beam with a transmission distance of 100 km, and the simulation analysis shows that the scheme can detect Laguerre-Gaussian beams with topological charge number -3 to +3.