Generation of a 56 GHz pulse train from a Fabry-Perot semiconductor laser using subharmonic optical injection

We have demonstrated the generation of 56 GHz pulses via mode-locking of a Fabry-Perot laser diode using subharmonic optical injection. This method does not require an intracavity saturable absorber and can also alleviate the requirement for high frequency drive electronics due to repetition rate multiplication. The generated pulse train exhibits low levels of timing jitter, and phase noise, and a large locking range.