Test and analysis of an electro-optic dynamic diverging lens for three-dimensional optical memories

We present the experimental results of a two-dimensional electro-optic dynamic diverging lens for dynamic imaging. The device is based on a lanthanum-modified lead zirconate titanate ceramic wafer. It produces a smooth phase-modulation distribution, which almost eliminates the diffraction loss of interdigital electrodes and the interference among different diffraction orders that exist in most of these types of devices. The continual change of focal length in this device is achieved by an applied control voltage. A dynamic-imaging system is demonstrated. It can be used to address three-dimensional optical memories. The aberration of the device as compared with an ideal lens is also numerically evaluated. With minor modification to the applied voltage distribution on the device, its performance is comparable with that of an ideal lens. (C) 1997 Optical Society of America.