Abstract

Several methods of one-way image transmission have been proposed in the past. Early methods¹ used conventional holography, and the recent ones have used nonlinear optics.² We present experimental studies of a nonlinear optical (i.e., real-time holographic) implementation of one early proposal.¹ This technique consists of first recording a hologram of an aberrator and then reading it out with an image beam that is distorted through the same aberrator. The hologram is formed by the interference between a plane-wave beam transmitted through the aberrator (objectbeam) and another plane-wave beam (reference beam). Any image beam traversing the same path as the object beam of the holographic recording, including the transmission through the aberrator, can thus be diffracted from the hologram and will yield the distortion-free original image. We have demonstrated this technique in real time by using a thin photorefractive strontium barium niobate crystal (0.7 mm thick) as the holographic medium. Preliminary results showed that the processed image resolution, as limited by the combination of our optics and the crystal, was ~70μm. The constraints of this technique on the crystal thickness, severity of aberration, and field of view will be discussed.

© 1990 Optical Society of America