A fiber laser using feedback from a linear and stationary cavity for mode locking

Bandwidth limited pulses of are shown in fig. 1. The pulse width decreases with increasing the repetition rate. The number of modes involved indicate that the pulses are formed by locking only a few modes. With no nonlinearity in the external cavity it would be first appear that APM is not the mode locking mechanism. It is hoped that experimental and theoretical studies which are under way will clarify the mode locking dynamics