Fig. 3

OAM spectrum results for different structured light. a The results of experimental single modes with TC from \(-\)10 to 10. Horizontal axis denotes different modes under test and longitudinal axis represents measured OAM spectrum. b Two selective results of experimental mul. modes. #1: mul. mode with equal weights. #2: mul. mode with random weights. Results of (a) and (b) are calculated based on 30 repeated experiments. Errorbar represents standard deviation. c Quantitative metrics to assess OAM spectrum measurement performance on different experimental datasets. Horizontal axis: index of each sample. R²: R-squared. MSE: mean squared error. d Model performance comparison on different datasets versus temperature value \(T\). Each MSE value is calculated through the average on the whole experimental dataset. Each \(T\) correspondes to a trained model. The opaque cyan region means that the models with corresponding \(T\) values are not converged during training. The vertical gray line marks the model in Fig. 2a – b. e – f OAM complex spectrum on simulated mode. Left: weight. Right: relative phase