Fig. 1. Flowchart of the GS algorithm^[14]

Fig. 2. Flowchart of the Z-value optimization

Fig. 3. Iterative process of the improved algorithm

Fig. 4. Curve of the Z-value optimization

Fig. 5. Simulation results of the optimized phase diagram. (a) Primary optimization phase; (b) quadratic optimization phase

Fig. 6. Schematic of the experimental light path

Fig. 7. Iteration result of the improved algorithm

Fig. 8. Iterative result of the MRAF algorithm

Fig. 9. Iteration result of the GS algorithm

Fig. 10. Simulation results of the triangular flat-top beam. (a) Phase obtained by the improved method; (b) intensity distribution of the output surface obtained by the improved method; (c) phase of the output surface obtained by the improved method; (d) phase obtained by the MRAF algorithm; (e) intensity distribution of the output surface obtained by the MRAF algorithm; (f) phase of output surface obtained by the MRAF algorithm; (g) phase obtained by the GS algorithm; (h) intensity distribution of the output surface obtained by the GS algorithm; (i) phase of the output surface obtained by the GS algorithm

Fig. 11. Experimental optical path

Fig. 12. Measured intensity distribution of the Gaussian beam

Fig. 13. Results of the optical experiment. (a) Result of the MRAF algorithm in CCD; (b) result of the improved algorithm in CCD; (c) result of the MRAF algorithm in beam quality analyzer; (d) result of the improved algorithm in beam quality analyzer