Fig. 1. Diffraction aperture and transmittance distribution

Fig. 2. Unilateral diffraction effect diagram of a rectangular aperture ring

Fig. 3. Calculation examples and results of CPS and ACPT

Fig. 4. Diffraction patterns for too low and too high Gaussian orders

Fig. 5. Gaussian order corresponding to the maximum combined contrast value under different topological charges

Fig. 6. Diffraction patterns of rectangular aperture with hard-edge or soft-edge and lateral light intensity distribution curves under different topological charges

Fig. 7. Diffraction pattern and lateral light intensity distribution curve of triangular aperture with hard-edge or soft-edge

Fig. 8. Schematic diagram of the experimental light path of the vortex beams diffracted by rectangular aperture with hard-edge or soft-edge

Fig. 9. Experimental light path diagram and physical diagram of rectangular aperture

Fig. 10. Experimental diffraction patterns and lateral light intensity distribution curves of rectangular aperture with hard-edge or soft-edge under different topological charges

Fig. 11. Contrast value and increase of the primary and secondary bright spot intensity in the diffraction pattern of the rectangular aperture with hard-edge or soft-edge obtained from the experiment

Fig. 12. Experimental diffraction patterns of rectangular aperture with hard-edge or soft-edge under different topological charges

Fig. 13. Increase in the contrast value of the primary and secondary bright spot intensity of the experiment and simulation