Fig. 1. Schematic of double-slit interference of LG beams. (a) Relationship between the phase difference and the y-coordinate when an l-th order LG beam illuminates the double-slit; (b) intensity patterns of different order LG beams without turbulence; (c) double-slit interference patterns of different order LG beams without turbulence; (d) double-slit interference patterns of different order LG beams under turbulence conditions (Cn2=2×10^-15 m^-2/3 and z=1000 m)

Fig. 2. OAM mode recognition system based on CACSIV3-Net. (a) Flowchart of the OAM mode recognition process based on CACSIV3-Net; (b) schematic diagram of the coordinate attention module; (c) schematic diagram of the cross-shaped window transformer

Fig. 3. Cross-Shaped Window Self-Attention

Fig. 4. Recognition effects of different network models on datasets. (a) Top-1 accuracy; (b) loss

Fig. 5. Ablation experiment. (a) ROC curve plot; (b) diagram of the model’s processing speed and total time consumption for OAM mode recognition; (c) model classification evaluation metrics

Fig. 6. Confusion matrix of CACSIV3-Net model on test set

Fig. 7. OAM mode F1-score under different levels of Gaussian noise standard deviation