Theoretical and experimental study on 10Gb/s all-optical packet clock recovery

Abstract

A novel 10Gbit/s all-optical packet clock extractor, which comprises a Fabry-Perot (F-P) filter and a semiconductor optical amplifier (SOA), is proposed in this paper. Low Finesse Fabry-Perot (F-P) filter was used to directly extract the packet clock from the data packet stream, which ensures that the clock locks fast and vanishes quickly. The clock, amplitude modulated as a result of low-Q filter, then goes into SOA to reduce the low-frequency amplitude noise. The impact of F-P filter and SOA on the locking and unlocking time of the packet clock is theoretically analyzed. The result shows that the locking time is reduced while the unlocking time is increased, due to the self-gain modulation (SGM) effect. We demonstrate instantaneous 10.075GHz clock extraction experimentally with the establishing time of about 8 code-periods and vanishing time of about 22 code-periods.