Novel coherent heterodyne optical time domain reflectometry for fault localization of optical amplifier submarine cable systems

A coherent, heterodyne-detection, optical time-domain reflectometry technique suitable for an all-optical repeater system is proposed. Rayleigh backscatter measurement through a 309-km bidirectional optical transmission line with six cascaded in-line semiconductor laser amplifiers is demonstrated using this technique. The possibility of fault localization on an optical amplifier system with optical isolators is shown.<
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