Ferroelectric Liquid Crystal Material with Low Birefrigence

Abstract
Ferroelectric liquid crystal (FLC) mixture with a low birefringence index (Δn ≤ 0.1) is developed. It consists of a three-component achiral matrix, which contains two phenacyl esters and one Demus ester, and a phenylpyrimidine derivative is used as a chiral dopant. The ferroelectric smectic C^* phase of the mixture exists in the temperature range from 18° C to 53° C. This mixture allows reducing of chromatic aberrations of ferroelectric liquid crystal cells because of a weaker birefringence dispersion compared with the known ferroelectric liquid crystals. The manufacturing technology of the electrooptical half-wave light modulators based on the developed mixture is much simpler than with the known FLCs, since the required thickness of the liquid crystal layer is inversely proportional to the birefringence magnitude.

Keywords: ferroelectric liquid crystal, phenacyl esters, Demus ester, birefringence index