Holographic grating recording in large area photoconducting liquid crystal panels

Large area (50 cm(2)) liquid crystal panels for optical information processing are evaluated. Optically-controlled diffraction gratings are reported in a dye-doped nematic confined between two transparent electrodes and SiO2 insulating layers. The electrodes are coated with unidirectionally treated alignment layers in order to form a 90 degrees twisted nematic structure. The parameters of the phase gratings obtained in a two-wave mixing experiment and light diffraction are controlled by applied voltage. The role of insulating layers is studied in respect of device performance and response time. (C) 2000 Elsevier Science S.A. All rights reserved.