A Miniature Photorefractive Circuit for Principal Component Extraction

The optical feature extractor is a photorefractive ring oscillator that can identify the strongest spatio-temporal component of its input space. The theoretical sections discuss the design and performance limitations of the signal extractor. A simple model of the filterʹs nonlinear functioning enables the reader to go directly to the experimental section that describes the making of the filter and experimental results. The device, also called the auto-tuning filter, is 5 cm^2 in size, has a 3 GHz processing bandwidth, and requires less than 5 mW of continuous optical power to operate.