High resolution optical A/D conversion using oversampling and interpolative coding

A novel approach to optical analog-to-digital (A/D) conversion based on oversampling and interpolative coding techniques is proposed. This approach incorporates the high resolution capabilities of classical oversampled A/D conversion with the high speed of optical processing technology to extend the resolution and conversion rates beyond those currently possible with other electronic or optical converters. The proposed optical converter uses optical threshold and arithmetic operators and fundamentally trades bandwidth for improving amplitude resolution. A non-interferometric realization using multiple quantum well electroabsorption modulators, photodetectors, and a novel approach for noninterferometric optical subtraction is described that can provide 8 bit resolution at a conversion rate of approximately 1 GHz