OPTICAL ANALOG TO DIGITAL COMPUTING

OPTICAL METHODS FOR ANALOG TO DIGITAL CONVERSION OFFER PROMISE FOR HIGHER SPEED AND HIGHER RESOLUTION THAN THAT ATTAINABLE BY ELECTRONIC MEANS. PARALLEL SAMPLING CONVERTERS, ALTHOUGH CONCEPTUALLY SIMPLE AND ELEGANT, HAVE SHOWN LITTLE PROGRESS BEYOND THE 1-2 GHZ, 2-4 BIT LEVEL ACHIEVED EARLY IN THE LAST DECADE. GREATER PERFORMANCE MAY BE AVAILABLE BY ADAPTING DELTA AND DELTA-SIGMA CONVERSION TECHNIQUES DEVELOPED FOR AUDIO AND VOICEBAND APPLICATIONS. THE DEVELOPMENT OF FIRST AND HIGHER ORDER OPTICAL DELTA MODULATORS, THEIR INCORPORATION INTO A/D AND D/A CONVERSION SYSTEMS, AND THE NECESSARY PROCESSING AND ENCODING OF OUTPUT DATA TO ACHIEVE AN OPTICAL ANALOG TO BINARY CONVERTER IS PROPOSED.