We investigate the characteristics of 40-GHz all-optical clock recovery based on a distributed Bragg reflector
(DBR) self-pulsating laser. With the injection of a low timing jitter clock signal, the timing jitter characteristics
of the DBR self-pulsating laser are investigated using both time domain and frequency domain methods. The
results reveal that the cause of the timing jitter in the recovered clock signal depends on the injected clock signal
power. The system performance of the clock recovery is investigated by the injection of a 40 Gb/s return-to-zero
on-off key (RZ-OOK) signal with a 2<sup>31</sup> - 1 pseudo random bit sequence (PRBS) pattern.