Vortex interactions revisited: Formation of stable elementary cells for creation of rigid vortex lattices

Optical vortices (OVs) are the only known truly two-dimensional phase dislocations. Because of their spiral phase fronts, the OV interaction results, in the simplest case (when two OVs are presented), in vortex mutual attraction/repulsion or in OV pair rotation. In this work we provide experimental evidences that a stable elementary cell forming the base for a large optical vortex lattice can be created by situating equally and singly charged OVs in the apices of a triangle and square and by nesting an additional control OV with an opposite unit charge in the center of the structure. Experimental data for the rotation of these triangular and quadratic elementary cells vs. OV-to-OV separation as well as the rotation of the same structures vs. propagation distance are presented. Generation and stable propagation of large rigid square-shaped and hexagonal OV lattices is demonstrated.