Polarization field and orientational order in liquid crystals

Abstract

Optical birefringence is a conveniently measurable quantity that is often used for determining the orientational order in uniaxial liquid crystals. The orientational order parameter is given by where agre and agr0 are the polarizabilities of the medium corresponding to the extraordinary and ordinary refractive indices, agrVerbar and agrboxhu are the corresponding values for a perfectly oriented medium with S = 1.