Diffraction of light by topological defects in liquid crystals

TL;DR

This paper investigates how light scatters when passing through topological defects in nematic liquid crystals, using a metric approach to model the effective spacetime geometry and analyze diffraction patterns.

Contribution

It introduces a metric-based framework to analyze light scattering by topological defects in liquid crystals, including new calculations for hedgehog and disclination defects.

Findings

Derived scattering amplitudes and cross sections for hedgehog defects.

Developed a cylindrical partial wave method for disclination defects.

Explored temperature effects on diffraction pattern localization.

Abstract

We study light scattering by a hedgehog-like and linear disclination topological defects in a nematic liquid crystal by a metric approach. Light propagating near such defects feels an effective metric equivalent to the spatial part of the global monopole and cosmic string geometries. We obtain the scattering amplitude and the differential and total scattering cross section for the case of the hedgehog defect, in terms of the characteristic parameters of the liquid crystal. Studying the disclination case, a cylindrical partial wave method is developed. As an application of the previous developments, we also examine the temperature influence on the localization of the diffraction patterns.