Phase synchronization of periodic and chaotic states induced by external optical injection in semiconductor lasers

We present results on a numerical simulation of phase synchronization of the periodic and chaotic states induced by optical injection in a semiconductor laser. Such states occur in an unstable part of the injection locking region. We find two branches of the stable periodic solutions (bistability) which are synchronized by the injected signal. We show that phase synchronization of the periodic states exists in the truncated period-doubling cascade to chaos and is maintained in some region of the chaotic states. We present a mapping of the region of synchronized chaotic states as a function of the amplitude and frequency detuning of the external optical injection.