Fig. 1. Generation process of DFOVL. (a)(d) Simulated intensity pattern and phase pattern of IG4,6,3e, respectively; (b)(e) simulated intensity pattern and phase pattern of IG4,6,4o, respectively; (c)(f) simulated intensity pattern and phase pattern of DFOVL, respectively

Fig. 2. Schematic of experimental setup

Fig. 3. Intensity distributions and phase distributions of DFOVLs with different level m. (a1)-(d1) Experimental intensity patterns of DFOVLs; (a2)-(d2) simulated intensity patterns of DFOVLs [Insets are phase masks used in experiments]; (a3)-(d3) simulated phase patterns of DFOVLs

Fig. 4. Interference patterns between DFOVLs and spherical wave. (a1)-(d1) Experimental interference patterns between spherical wave and DFOVLs; (a2)-(d2) simulated interference patterns between spherical wave and DFOVLs

Fig. 5. Experimental intensity patterns and spherical wave interference patterns of DFOVLs at different waist radius [Insets in Fig. 5(b1) are 3× magnification of interference patterns between positive and negative optical vortex beams and spherical wave, respectively; insets in Figs. 5(a1)-(a12) are phase masks used in experiments]. (a1)-(a12) Experimental intensity patterns; (b1)-(b12) spherical wave interference patterns

Fig. 6. Intensity distributions and spherical wave interference patterns of DFOVLs for different phase difference φ. (a1)-(a12) Experimental intensity patterns of DFOVLs (insets are phase masks used in experiments); (b1)-(b12) experimental interference patterns between spherical wave and DFOVLs