Fig. 2: Experimental demonstration of vortex transport along a single channel in topological disclination.
From: Topological orbital angular momentum extraction and twofold protection of vortex transport
a, A laser-written photonic lattice featuring C3-rotational symmetry and chiral symmetry with a single-site disclination core, where a dashed white circle marks the core location for excitation with a vortex beam. b, (1–3) 3D intensity plots of the experimental results showing that an input vortex (1) expands dramatically in free space without TVG (2), but it is well guided after propagating through the disclination core with TVG (3). c, (1) Intensity pattern of the input vortex beam; (2) output intensity distribution and (3) interferogram of a single-charge \(l=1\) vortex beam after 20 mm of free propagation without the lattice, where the spiral fringes exhibit vorticity; output intensity pattern of the vortex beam after propagating through the disclination lattice from (4) experimental measurement and (5) numerical simulations. d, (1–5) Results corresponding to (c, 1–5) but obtained for a high-order vortex with a topological charge \(l=2\). The top-right insets in (4) and (5) are interferograms to identify the vortex phase singularity.
