Optical clock system with optical time delay means

Abstract

An optical clock system for high-performance computing systems uses unique methods of clock generation, delay timing, and electrical clock conversion to eliminate clock skew due to passive circuit elements. There is provided a direct optical connection to active devices in the computing system thereby eliminating the transmission of electrical clock signals through passive transmission elements. The optical clock system eliminates several stages of clock drivers and, as a result, is capable of reducing clock skew due to active circuit skew as well. In one embodiment, an optical pulse timing operator (10) produces ultrashort pulses which are equally divided by an 1-by-N splitter (16) into N optical fibers (18), where N depends on the number of clock signals required. Each fiber has a different length, resulting in different propagation times for the optical pulses. The light from each of the N fibers are again split into M fibers by N 1-by-M splitters (20), where M depends upon the number of distribution points for the clock. The N.times.M fibers are regrouped to form a bundle of N fibers, and these M fiber bundles are then coupled to each module (22) where the delayed optical signals are converted into the appropriate electrical clock signals.