Transition to pulsed operation in short external-cavity FM semiconductor lasers

Conditions are established for the occurrence of a transition from FM operation to pulsed output in short external-cavity FM semiconductor lasers. It is shown that there are dual operating points around which FM operation is possible. The position of the modulation frequency in relation to these two FM operating frequencies determines the type of behavior exhibited by the configuration. In particular, pulsed and mixed pulsed-FM behavior is observed when the modulation frequency is between the two possible FM operating frequencies.