(a), (b) Micrographs of fabricated LC holographic plates corresponding to Hopf link and Trefoil knot, respectively. The sizes of the pattern areas are both 1 mm×1 mm. (c) Experimental setup for configuring and detecting vortex links and knots. The CCD is fixed on a linear translation stage to implement the scanning of the output field along z direction. BS₁ and BS₂, beam splitters; L₁ and L₂, lenses; M₁ and M₂, mirrors; PH, pinhole; P, polarizer; LC, liquid crystal holographic plates; λ/4, quarter wave plate.