Abstract:A novel method for generation of high-energy femetosecond pulses directly from mode-locked Er~(3+)-doped fiber(EDF) laser that is constructed entirely with abnormal dispersive fibers,is proposed by using lumped amplifier and high-output-loss coupler.The results shows that the combination of lumped amplification and high output could effectively reduce the average intra-cavity nonlinearity,lower the periodic perturbation and permit high-energy,broad bandwidth pulses to be formed.By using nonlinear polarization evolution technique,the stable mode-locked optical pulses with energies of more than 1 nJ.pulse duration of about 200 fs,and spectral width of 18.0 nm at a 14.0 MHz repetition rate were obtained from the presented fiber laser successfully.The self-starting pump threshold is lower than 20 mW.