Fig. 1. Schematic diagram of optical path for dual-optical path interferometry

Fig. 2. Composition diagram of control system for dual-optical path interferometry

Fig. 3. Flow chart of system debugging for dual-optical path interferometry

Fig. 4. Interference fringe images in actual measurement

Fig. 5. Flow chart of switching structure

Fig. 6. Structure diagram of position limit protection

Fig. 7. Schematic diagram of calibration

Fig. 8. Relationship between speckle contrast and rotational speed of frosted glass

Fig. 9. Relationship between fringe contrast and rotational speed of frosted glass

Fig. 10. Relationship between fringe signal-to-noise ratio and rotational speed of frosted glass

Fig. 11. Relationship between voltage and rotational speed of frosted glass

Fig. 12. Relationship between voltage and interference fringe

Fig. 13. Man-machine interaction interface

Fig. 14. Contrast measurement results of frosted glass

Fig. 15. 100 mm aperture two switch measurement results

Fig. 16. 450 mm aperture two switch measurement results