980 nm all fiber NPR mode locking Yb doped phosphate fiber oscillator and its am

We report on a 980 nm all-fiber passively, mode-locking Yb-doped phosphate fiber oscillator with the nonlinear polarization rotation (NPR) technique and its amplifier. In order to obtaining the stable selfstarting mode-locking oscillator at 980 nm, a bandpass filter with 30 nm transmission bandwidth