Fig. 1. A neutral density filter and transmittance curves

Fig. 2. Characteristics of the modulation plate. (a) Radial distribution of the transmissive region; (b) Ideal modulation plate; (c) Finished modulation plate (part of the plate)

Fig. 3. Preparation process of the modulation plate

Fig. 4. Transmittance curve of the modulation plate obtained

Fig. 5. Results of beam pointing control simulation. (a) Iteration curves of performance metric; (b) Initial and (c) final positions of the spot with a gain of 0.01

Fig. 6. Schematic diagram of the experimental platform

Fig. 7. Results of the transmittance verification experiment and the beam pointing control experiments. (a) Normalized transmittance curves obtained from experiment and simulation; (b) Normalized energy curves of 10 sets of beam pointing control experiments

Fig. 8. Initial and final positions of spots. (a) Combination of ten sets of images; (b) Centroid extraction results of the spots; (c) Magnified display of the final position region of the spots