An active mode-locked fiber ring laser based on XGM in SOAs is demonstrated with an external pulse sequence. The
laser operates at a variable repetition rate from 1GHz to 15GHz, even up to 40GHz with an additional fiber-based
multiplexer. By a wavelength tunable filter, a wide wavelength tunable span about 37nm is achieved continuously
between 1528nm to 1565nm. Without any pulse compression device, the pulse sequence with low pulsewidth about 12ps
and high output power about 9dBm can be obtained in different operation repetition rate. The output pulses show a time
jitter low than 180fs in all operation repetition rate. A detailed analysis is done experimentally to investigate the
relationship between parameters of the SOA-based fiber ring laser and pulsewidth of the generated mode-locked pulses.