Ultralow timing jitter 40-Gb/s clock recovery using a self-starting optoelectronic oscillator

We demonstrate clock recovery with ultralow timing jitter by using a novel self-starting optoelectronic oscillator that is based on an electroabsorption modulator in a fiber extended cavity. The oscillator simultaneously generates a 10-GHz-rate microwave signal and a train of 15-ps optical pulses with ∼40-fs timing jitter in the 100-Hz to 1-MHz range. Under direct optical-injection locking of the oscillator, we demonstrate simultaneous error-free extraction of both the electrical and the optical clocks of 10-GHz rate from either a single-channel 10-Gb/s return-to-zero data stream or a four-channel 40-Gb/s optical time-division-multiplexed data stream.