3-TERMINAL ADAPTIVE NEMATIC LIQUID-CRYSTAL LENS DEVICE

A 1 mm x 1 mm nematic liquid-crystal three-terminal device for optical beam forming (focusing/spoiling) is fabricated. A thin-film-resistor network on the device substrate layer is used to control the voltages on the 98 internal lens electrodes by use of only one variable externa l driver. By using a high-resistance thin-film layer of amorphous sili con under the 98-element parallel electrode structure layer, we genera te a near-continuous index perturbation to form a cylindrical lens. Th e focal length of this lens is continuously variable from infinity to 12 cm by use of a variable 1-4-V-peak 1-kHz square-wave external termi nal control signal.