Fig. 1. Experimental optical path

Fig. 2. Phase distributions calculated by different encoding methods. (a) Method 1; (b) method 2

Fig. 3. Intensity distributions at back focal plane obtained by different methods

Fig. 4. Structural similarity index S versus different parameters. (a) w; (b) r0; (c) α

Fig. 5. Diffraction efficiency η versus different parameters. (a) w; (b) r0; (c)α

Fig. 6. Schematic of experimental device

Fig. 7. Intensity distributions at back focal plane. (a) Method 1; (b) method 2

Fig. 8. Experimental intensity distributions at back focal plane along y direction. (a) Method 1; (b) method 2