Fig. 1. Experiment setups. (a) Er－doped fiber oscillator; (b) fiber pre－amplifier; (c) main－amplifier; (d) schematic of pulse divider with eight replicas; (e) fiber compressor

Fig. 2. Combining efficiencies and output powers under different pre－amplifier output pulse durations. (a) Combining efficiency versus main－amplifier pump power; (b) output power of Port A versus main－amplifier pump power；(c) output power of Port B versus main－amplifier pump power

Fig. 3. Spectra and auto－correlograms. (a) Output spectra of pre－amplifier and main－amplifier; (b) intensity autocorrelation traces of main－amplifier output pulse; (c) output spectrum after compression; (d) intensity autocorrelation traces of output pulse after compression