The present invention provides a device that acts as an optical switch to control the intensity of a light beam through the action of a second control beam. This behavior is achieved through photoinduced anisotropy that develops in a monomolecular layer coating the inside surfaces of a liquid crystal cell. One of the surfaces is permanently aligned prior to assembly by illuminating the surface with polarized light in the presence of oxygen. The other surface retains reversible behavior, adapting anisotropy according to the orientation of the polarization of the control beam. Accordingly, an optically controlled liquid crystal light valve is provided that does not require contact-rubbing methods in order to permanently align one of the layers coating an inside surface of the cell.
The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of DMR-0213918 awarded by the National Science Foundation.