Abstract

Actively mode-locked lasers produce pulses with excellent stability, however pulses are much longer than those obtained by passive modelocking. On the other hand, the mechanism for self-stabilization of the pulse period in passively mode-locked lasers is very weak resulting in pulse trains that are not equally spaced.¹ We have developed a fiber laser passively mode-locked with a semiconductor saturable absorber mirror (SESAM) that uses amplitude modulation to produce an equally spaced pulse train. The important aspect of this study is that active pulse synchronization was achieved without changing the pulse shape generated passively. We have found that harmonic suppression and time ordering are significantly improved for optimal amplitude modulation.

© 2002 Optical Society of America