A POLARIZATION-MAINTAINING AND DISPERSION-MANAGED 10-GHZ MODE-LOCKED ERBIUM FIBER RING LASER PROVIDING BOTH SECH(2)-SHAPED AND GAUSSIAN-SHAPED PULSES

We have constructed a polarization-maintaining and dispersion-managed 10-GHz regeneratively mode-locked Erbium fiber ring laser which genera tes highly stable and nearly transform-limited 3.5- to 7-ps sech(2) pu lses at 1560 nm. By forcing the wavelength to a narrow-band ripple in the transfer function of the laser in-line filter, highly stable 15-ps Gaussian-like pulses were also obtained. We have studied in detail th e temporal and spectral shapes of the pulses and confirmed a good agre ement with the corresponding theoretical fits for transform-limited se ch2 and Gaussian pulses, respectively. The pulses have a timing jitter below 0.2 ps and the highest reported supermode noise suppression cf 90 dB. This remarkably high supermode noise suppression is likely a re sult of the dispersion-management in the laser cavity. The wavelength is tunable within 1530-1570 nm. The laser has excellent long-term stab ility and is very robust to thermal and mechanical disturbances, (C) 1 998 Academic Press.