During the past two decades, fiber mode-locked laser with its compact structure,excellent performance and stable mode-locked state, is becoming a promisingwork-horse in ultrafast laser technology, causing a growing number of researchscientists’interest.In recent years, different dispersion structures and different mechanisms of fibermode-locked lasers have enriched the theoretical basis, and improved the ultrashortpulse technology. The Stretched-Pulse mode-locked laser which generates largelinear chirp pulses and its breathing cavity evolution is quite suitable as a seedsource for fiber chirped pulse amplification(CPA) system. In this paper, a 67 mWaverage power, 36 MHz mode-locked pulse output repetition rate mode-lockedlaser is achieved. Its time-domain pulse width has been compressed to 70 fs afterthe extracavity compensation.Due to the all fiber structure without dispersion compensation device, the allnormal dispersion(ANDi) mode-locked laser is more simple, more stable. At thesame time, large-mode-area photonic crystal fiber can provide higher performancemode-locked pulses, because its large mode area reduces the nonlinear effects. Inthis paper, a combined system based on the previous two elements is establishednaturally. Generates 4 W average power, 54 MHz repetition rate mode-lockedpulse, the time-domain pulse width is compressed to 140 fs after extracavitycompensation.Finally, the compression technique based on nonlinear photoniccrystal fiber istheoretical and experimental analysed, carrying out the result of a compressionfrom 1 ns to 800 ps. |