Singular polarimetry: Evolution of polarization singularities in electromagnetic waves propagating through a weakly anisotropic medium

摘要

We describe the evolution of a paraxial electromagnetic wave characterizingby a non-uniform polarization distribution with singularities and propagatingin a weakly anisotropic medium. Our approach is based on the Stokes vectorevolution equation applied to a non-uniform initial polarization field. In thecase of a homogeneous medium, this equation is integrated analytically. Thisyields a 3-dimensional distribution of the polarization parameters containingsingularities, i.e. C-lines of circular polarization and L-surfaces of linearpolarization. The general theory is applied to specific examples of theunfolding of a vectorial vortex in birefringent and dichroic media.