Algebra of optical dislocations with plasmonic nanostructures

Plasmonic structures with physical and Berry-type dislocations are shown to produce vortices with phase singularity according to the system and illumination parameters. We demonstrate that, by combining the two types of dislocations in one structure, the manipulation with the topological charge of the emerging vortex beams can be controlled in an intriguing way. As a result, the plasmonic field distribution can be conveniently modified and selectively excited.