Fig. 1. Schematic overview of experimental setup to realize the optical vortex copier via type-II second-harmonic generation in the Fourier domain (see the text for details). Insets (a) and (b) show the initial array of Gaussian spots in Path 1 and the single vortex in Path 2, respectively.

Fig. 2. Experimental observations of the optical vortex copier. (a) and (d) Initial structured arrays of fundamental Gaussian spots. Single vortex with (b) l=1 and (c) l=2. Superposition of two vortices with (e) l=±1 and (f) l=±2.

Fig. 3. Schematic overview of the experimental setup to realize the optical regenerator (see the text for details). Insets (a), (b), and (c) show the initial array of two single vortices, the corresponding results of self-convolution, and the resultant array after the cylindrical lens, respectively.

Fig. 4. Experimental observations of the optical vortex regenerator with different arrays of single vortices. Top panel: Initial input arrays encoded in 1064 nm fundamental lights. Middle: Regenerated arrays encoded in 532 nm SHG light fields. Bottom: Measurements of topological charges with a cylindrical lens.

Fig. 5. Experimental observations of the optical vortex regenerator with an array of vortex superposition states. (a) Numerical simulation of input array. (b) Output array.