The inherent birefringence of liquid crystals means that the index of refraction seen by an incident light depends on the relative angle between the polarization of the light and the long axis of the liquid crystal molecules. This property allows the liquid crystal film to be used as a polarization rotator. Since we can alter molecular orientation with an applied field, we can control the degree of polarization rotation. In this way, we can alter light transmission between a pair of crossed polarizers. This type of device provides exceptional light blocking and fast response time. AlphaMicron has demonstrated the first polarizer based devices on curved flexible plastic substrates for intense light protection.
