Wavelength-tunable Yb-doped passively Q-switching fiber laser based on WS2 saturable absorber

We have fabricated an Yb-doped passively Q-switching fiber laser based on WS2 saturable absorber. Both the operating wavelength and the repetition rate can be tuned in a wide range. The operating wavelength can be continuously tuned from 1027 nm to 1065 nm under the Q-switching state at a fixed pump power, while the repetition rate increases from 60.2 kHz to 97.0 kHz by varying pump power at a fixed wavelength of 1048.1 nm. The shortest pulse duration of 1.58 mu s was observed. To the best of our knowledge, it's the first demonstration of WS2-based passively Q-switching fiber laser with a wide tunable range at 1.0 mu m band. (C) 2015 Optical Society of America