Conoscopic patterns in photonic band gap of cholesteric liquid crystal cells with twist defects

TL;DR

This paper theoretically studies how incidence angles affect light transmission and conoscopic patterns in cholesteric liquid crystal cells with twist defects, revealing how defect angles influence resonance rings and polarization patterns.

Contribution

It introduces a detailed theoretical analysis of conoscopic patterns and polarization effects in cholesteric liquid crystals with twist defects, highlighting the impact of defect angles on optical resonances.

Findings

Resonance rings shrink and disappear as defect twist angle increases.

Incidence angles significantly influence polarization-resolved patterns.

Defect angle induces rotation of conoscopic images.

Abstract

We theoretically investigate into the effects of the incidence angles in light transmission of cholesteric liquid crystal two-layer sandwich structures with twist defects created by rotation of the one layer about the helical axis.The conoscopic images and polarization resolved patterns are obtained for thick layers by computing the intensity and the polarization parameters as a function of the incidence angles.In addition to the defect angle induced rotation of the pictures as a whole, the rings of defect mode resonances are found to shrink to the origin and disappear as the defect twist angle varies from zero to its limiting value and beyond.