816 nm All-Fiber Mode-Locked Tm-Doped Laser in Noise-Like Pulse Regime

We report, to the best of our knowledge, the firstall-fiber passively mode-locked laser around 800 nm wavelength.The laser with a figure-9 cavity configuration consists of a home-made 1146 nm Raman fiber laser as pump source, a 2.1 m-lengthTm(3+)-doped ZBLAN fiber, a 0.8/1.15 mu m fiber end-facet dichroicmirror, and a nonlinear optical loop mirror (NOLM). The NOLMis not only employed as the output cavity mirror, and also initiatespassive mode-locking. The mode-locked center wavelength is816 nm with a 3-dB bandwidth of similar to 0.35 nm. The mode-lockedrectangular pulse in the noise-like regime has a pulse durationof 486.7 ps with the 7.826 MHz repetition rate. The maximumaverage power is as high as 488.5 mW and the pulse energy is62.4 nJ. This work represents an important step towards similar to 800nm short-wavelength ultrafast fiber lasers and may has potentialapplications in biological imaging and medical treatment.