Polarization singularities in the self-focusing of an elliptically polarized laser beam in the isotropic phase of a cholesteric liquid crystal close to the temperature of mesophase transition

Abstract

Self-action of an initially elliptically polarized Gaussian beam in the isotropic phase of a cholesteric liquid crystal near the temperature of phase transition is studied. It is shown that nonlocality of the optical properties of the crystal leads to significantly different self-action behavior of light beams with right-hand and left-hand elliptical polarization. Numerous lines of circular polarization singularity (C-lines) can appear in beam cross sections during its self-focusing. These lines are circumferences of various radii with centers located on the beam axis and lying in planes perpendicular to the direction of its propagation. The position and contrast of the lines is subject to the total beam power and initial polarization state, and in certain cases some of the singleC-lines split into multiple lines, and vice versa.