This paper describes several photorefractive devices for optical information processing that have been developed in recent years. These include photorefractive spatial light modulators; numerical processors, such as parallel integrator and matrix-matrix multiplier; devices for optical neural network applications, such as parallel thresholding, Max operation and perceptron learning.
John H. Hong,
"Photorefractive devices for optical information processing", Proc. SPIE 1562, Devices for Optical Processing, (1 December 1991); doi: 10.1117/12.50768; https://doi.org/10.1117/12.50768