Liquid crystal rotatable waveplates

We propose and demonstrate rotatable waveplates using liquid crystal for the first time which can be used for polarization control. To realize a waveplate with an arbitrary direction of birefringence, we use a vertically-aligned nematic liquid crystal cell with a lateral electric field. The orientation of the waveplate can be rotated endlessly. It was confirmed that the direction of the waveplate could be rotated endlessly at a rate of 7200/spl deg//s, which is sufficient to construct polarization controlling devices for most SMF transmission systems.