Fig. 1. Composition diagram of system

Fig. 2. Diagram of measurement principle

Fig. 3. Theoretical model of depth calibration

Fig. 4. System optical path

Fig. 5. Variation curves of gray contrast of group 7 element 1 with object distance

Fig. 6. Image obtained from resolution target taken by imaging system

Fig. 7. Contrast fitting line of each element in group 7

Fig. 8. Fringe patterns containing height difference information taken in different areas of field of view

Fig. 9. Fringe width and its rate of change curve

Fig. 10. Surface quality of measured object

Fig. 11. Fringe pattern with width of 8.96 μm