Fig. 1. Autofocus schematic based on axicon mirror

Fig. 2. Distribution of parallel beams through biaxial axicon mirrors

Fig. 3. Half-ring beam segmentation diagram

Fig. 4. Magnification of object multilayer reflection

Fig. 5. Diagram of parallel Gaussian beam passing through an uniaxial axicon mirror in cylindrical coordinates

Fig. 6. Autofocus system construction based on ZEMAX

Fig. 7. System verification. (a) Color-free verification; (b) defocusing simulation verification

Fig. 8. Half-ring beam analysis. (a) Intensity curve of Fraunhofer diffraction for half-ring beam; (b) PSF distribution in y direction at focal plane

Fig. 9. Beam quality analysis. (a) Beam distribution behind axicon mirror; (b) light energy simulation based on Tracepro

Fig. 10. Autofocus system experimental platform building diagram

Fig. 11. Experimental verification. (a) Multilayer experimental verification; (b) diffraction effect of light source; (c) system resolution verification