Clock recovery by a fiber ring laser employing a linear optical amplifier

We report on subharmonic optical clock recovery (OCR) at 10 GHz from 160-Gb/s optical time-division multiplexed signals. The OCR circuit is based on a passively mode-locked principle in a fiber ring laser that utilizes fast gain dynamics of a linear semiconductor optical amplifier. To decrease the jitter amount in the clock pulse considerably, postelectrical signal processing is performed. The recovered clock is a 1.8-ps 10-GHz pulse train with 0.37 pulsewidth-bandwidth product.