Fig. 1. Schematic of periodic blazed grating (BG)^[17]

Fig. 2. Phase grayscale maps generated with different methods. (a) Composite phase method; (b) sub-aperture method; (c) iterative Fourier transform (IFT) method

Fig. 3. Simulation result of one-dimensional far-field normalized light intensity (NLI) distribution for double-beam

Fig. 4. Simulation results of far-field NLI distribution for double-beam. (a)-(c) Two-dimensional diagrams generated using composite phase method, sub-aperture method, and IFT method, respectively; (d)-(f) three-dimensional diagrams generated using composite phase method, sub-aperture method, and IFT method, respectively

Fig. 5. Experimental results of two-dimensional far-field light intensity distribution for double-beam. (a) Composite phase method; (b) sub-aperture method; (c) IFT method

Fig. 6. Experimental block diagram of synchronous beam tracking and aiming for double-target

Fig. 7. Algorithm flowchart of synchronous beam tracking and aiming for double-target

Fig. 8. Beam tracking results of single target moving at different speeds. (a) Tracking trajectory; (b) error curve

Fig. 9. Beam tracking results of double-target moving at speed of 2 mm/s. (a) Tracking trajectory; (b) error curve

Fig. 10. Beam tracking results of double-target moving at speed of 3 mm/s. (a) Tracking trajectory; (b) error curve

Fig. 11. Beam tracking results of double-target moving at speed of 4 mm/s. (a) Tracking trajectory; (b) error curve

Fig. 12. RMSE between actual and estimated values of spot positions with their corresponding BCRLB when double-target moves