Fig. 1. Vortex phase distribution and amplitude distribution under different topological charges. (a)-(c) Vortex phase distribution;

Fig. 2. Speckles formed by vortex beam passing through strong and weak scattering media. (a)(d) Amplitude distribution patterns of vortex beam; (b)(e) speckle patterns after vortex beam passing through strong scattering medium; (c)(f) speckle patterns after vortex beam passing through weak scattering medium

Fig. 3. Experimental optical path diagram of vortex beam passing through strong scattering medium

Fig. 4. Speckle patterns formed by vortex beams with different topological charges passing through scattering medium

Fig. 5. Speckle pattern and local magnification of vortex beam with different topological charges. (a) l=1; (b) l=10

Fig. 6. Neural network structure

Fig. 7. Curves of training loss and validation loss in 10 epochs

Fig. 8. Curves of training accuracy and validation accuracy in 10 epochs

Fig. 9. Accuracy of prediction

Table 1. Parameter setting of each layer of neural network