Fig. 1. Principle of laser differential confocal-interference element parameter measurement

Fig. 2. Differential confocal response curves

Fig. 3. Laser differential confocal interferometry multi-parameter measurement. (a) Laser differential confocal interferometry optical path; (b) interferometric spherical surface; (c) curvature radius; (d) ultra-large curvature radius; (e) focal length; (f) ultra-long focal length; (g) thickness; (h) refractive index

Fig. 4. Ultra-large curvature radius measurement principle

Fig. 5. Ultra-long focal length measurement principle

Fig. 6. Thickness and refractive index measurement principle

Fig. 7. Frame of laser differential confocal high precision measurement system

Fig. 8. Laser differential confocal-interference high-precision measurement instrument

Fig. 9. Interfaces of measurement software. (a) Differential confocal measurement control interface; (b) differential confocal parameter measurement and analysis interface; (c) phase shift interferometry interface; (d) real-time display and adjustment interface