Fig. 1. Translation-rotation scanning principle diagram

Fig. 2. Schematic of coordinate transformation geometry

Fig. 3. Optical schematic of the differential confocal sensor

Fig. 4. Normalized axial response intensity of different angle

Fig. 5. Angle-dependent coincidence difference （β=0）

Fig. 6. Schematic diagram of spatial constraints

Fig. 7. Schematic diagram of envelope area

Fig. 8. Schematic diagram of equivalent cone

Fig. 9. Algorithm simulation schematic diagram

Fig. 10. Laser differential confocal surface measurement system

Fig. 11. Off-axis aspheric surface profile measurement results

Fig. 12. Profile measurement results of 20° tilted surface