A fiber Chirped Pulse Amplification (CPA) laser system that includes a fiber mode-locking oscillator for generating a seed laser for projecting to a stretcher for generated a pulse-stretched laser for projecting to a multiple stage amplifier. The multiple stage amplifier further amplifying said laser for projecting to a compressor for compressing said laser to generate an output laser of an original pulse width. In this invention, pulse stretcher is implemented with a special dispersion management fiber that has a flat dispersion or a negative TOD (dispersion slope, or a slope of dispersion versus wavelength).