Tilt Angle Measurement on a Homogeneously Aligned Liquid Crystal

Abstract We have measured tilt angles in a homogeneously aligned liquid crystal (LC) cell on a glass substrate. These measurements are made as a function of polyvinyl alcohol (PVA) concentration in water, number of rubs, sample thickness and temperature. The liquid crystals used are E-31 and E-310 (E. Merck). For E-310 material, the tilt angles are 2.10 ± 0.50 and 2.50 ± 0.50 degrees for 20 and 60 micron thick samples respectively and are independent of temperature within the accessible range of 25rubs and is optimum at 40 rubs, beyond which it makes no effect up to 250 rubs.