We investigate the effects of a piece of zero-dispersion fiber(ZDF) on the pulse dynamics of a passively mode-locked fiber laser operating in the stretched-pulse regime.Numerical simulation suggests that the proper location and length of ZDF facilitate spectrum broadening and pulse shortening in fiber lasers while maintaining constant net cavity dispersion.A nonlinear polarization evolution mode-locked Er-doped fiber laser with a dispersion map is built based on the simulation.Larger optical spectrum broadening is obtained by inserting a longer ZDF after the active fiber during single-pulse operation,which well agrees with the simulation.
We demonstrate an all-fiber, high-power, and high stability ultrafast laser source operating at 1563 nm. A highly stable, self-starting carbon nanotube(CNT) mode-locked femtosecond fiber laser is used as the seed source. The amplifier stage uses a fiber chirped pulse amplification configuration. The main power amplifier is based on a cladding-pumped Er–Yb co-doped fiber with 10 μm active single-mode core diameter. The laser source provides 3.4 W average output power at 75 MHz repetition rate. The pulses are compressed to 765 fs by a low-loss transmission grating pair. The robust, compact, and high-power 1560 nm fiber laser source can be used for eye surgery and solar cell micromachining.
