Phase engineering methods in polarization singularity lattice generation

Abstract

Polarization singularity lattices exhibit richer features and varieties than their scalar counterparts, namely phase vortex lattices. Lattices consisting of only C-points or only V-points of different Stokes indices are possible by phase and polarization engineering. In this article we show the generation of one generic and three non-generic lattices—all abiding the enlarged sign principle in six-beam interference. Two of them are vector fields and two of them are ellipse fields. In the vector fields, one lattice consists of V-points of the same magnitude and the other consists of V-points of different magnitude of the Poincare-Hopf index. Similarly in the two ellipse fields, the same and different C-point index lattices are there. Interestingly all the C-points are of the same handedness. In one particular case the C-point lattice is interlaced with saddle points, in which formation of C-lines is also noticed. These are saddles in both azimuth and ellipticity distributions. The governing rules for realizing these lattices are given and these lattices are experimentally demonstrated.