NOISE-REDUCTION BY HARMONIC INJECTION LOCKING OF PASSIVELY MODE-LOCKED ERBIUM-DOPED FIBER LASERS

Harmonic injection locking can generate pulse trains at high repetition rates from passively made-locked lasers. We have examined experimentally the mutual interaction of noise with the locking process. For injected signals with large timing and amplitude noise, the mode-locked fiber laser generated a pulse train with reduced noise. Injected signals with low timing and amplitude noise were employed for the reduction of the internal noise of the passively mode-locked laser. The achieved output pulse-to-pulse timing jitter in the range of 20-2500 Hz was similar to 0.6 ps, comparable with that of actively stabilized fiber lasers. (C) 1995 Optical Society of America