Fig. 1. Schematic diagram of optical element surface scattering image acquisition device

Fig. 2. Scattering distribution diagram of the same position of the optical element under different exposure times

Fig. 3. Multi-exposure scattering image fusion flowchart

Fig. 4. Flow chart of fusion of low-frequency components with the strongest principle of scattered signal

Fig. 5. Scattering distribution map with large dynamic range

Fig. 6. Coordinate relation diagram of bidirectional scattering distribution function

Fig. 7. Distribution of relative scattered light power at different exposure times

Fig. 8. Fusion results of different fusion methods

Fig. 9. Relative scattered light power distribution map obtained by different fusion methods