Using an erbium-doped fiber laser (EDFL) passively mode lacked by a se
miconductor saturable absorber, we generate 5.5-ps pulses of a 2.3-nJ/
pulse, which are more than three times higher in energy than for other
reported EDFL's. We show that, by introduction of a Linear loss eleme
nt within the cavity, multiple pulsing behavior at high pump powers ca
n be suppressed. We also determine the saturable-absorber characterist
ics-absorbance versus wavelength near band gap-that are necessary to p
roduce short mode-locked pulses.