Two types of fast switching mixtures with high positive dielectric anisotropy were described. The first type, with a birefringence
below 0.3, was designed for devices operating at room or lower temperatures and the second one, with a birefringence higher
than 0.3 for devices operating at elevated temperatures.
Keywords isothiocyanatobiphenyls - isothiocyanatoterphenyls - isothiocyanatotolanes - phase transitions - nematic high birefringence mixtures