A learning and recall algorithm for optical associative memory based on the conventional correlation-learning method with three effective improvements (sparse-encoding method, constant-total-activity method, and binary memory) is proposed from a viewpoint of practical implementation. It is shown that the algorithm is suitable for implementation with a bistable spatial light modulator such as a ferroelectric liquid-crystal spatial light modulator, which has high resolution and a fast response time. The results of theoretical analysis and simulations indicate that the algorithm permits an associative-memory system with a large memory capacity to be realized. An example of an optical system for executing this algorithm is proposed. To determine the performance specifications that are required for the various optical components within the system, we simulate and evaluate the effect of noise (which is caused by nonideal components) on system performance. These results show that the system is robust in the presence of predicted noise levels.
© 1995 Optical Society of America
Original Manuscript: August 30, 1993
Revised Manuscript: December 19, 1994
Published: June 10, 1995
Haruyoshi Toyoda and Masatoshi Ishikawa, "Learning and recall algorithm for optical associative memory using a bistable spatial light modulator," Appl. Opt. 34, 3145-3151 (1995)