Optical Implementation of a Self-Organizing Feature Extractor

We demonstrate a self-organizing system based on photorefractive ringoscillators. We employ the system in two ways that can both be thought of as feature extractors; one acts on a set of images exposed repeatedly to the system strictly as a linear feature extractor, and the other serves as a signal demultiplexer forfiber optic communications. Both systems implement unsupervised competitive learning embedded within the mode interaction dynamics between the modes of a set of ring oscillators. Aftera training period, the modes of the rings become associated withthe different image features or carrier frequencies within the incoming data stream.