Abstract
A highly sensitive photoelectrical reorientation effect in nematic liquid crystals has been investigated. The effect occurs under the combined application of DC-electrical fields and low power illumination. It was first observed in nematic liquid crystals of discotic molecules1,2,3 but was recently also obtained with calamitic, i.e. rod-like molecules, as will be shown here. The observed optically nonlinear behavior can be characterized by rather large coefficients up to 0.5 cm2/W.