Book Description

Two new techniques for making computer generated spatial filters with high dynamic range and high light efficiency are described, and a general treatment of computer generated holograms is given. Examples of single-channel (continuous phase control) phase-only filters, binary phase-only filters, as well as the absorption-type filters have been realized experimentally. Experiments have been carried out for correcting blurred images and for character recognition. Finally, a ternary hologram (binary absorption and binary phase), which preserves advantages of both types of binary holograms but is capable of a higher dynamic range than either individually, has been realized experimentally using color film. (Modified author abstract).