Self-Starting Mode-Locking by Fiber-Integrated WS2 Saturable Absorber Mirror

We reported on a novel configuration of fiber-integrated tungsten disulfide (WS2) saturable absorber mirror (SAM). The SAM, fabricated by deposition of WS2 layer and Au film over fiber end based on the magnetron sputtering technique, was compact, reliable, and suitable for mass production. The modulation depth, saturation intensity, and reflectivity weremeasured to be 4.48%, 138 MW/cm(2), and 98%, respectively. By employing this SAM, self-starting mode locking could be achieved in a wideband range in linear erbium-doped fiber lasers. The output pulsewidth was around 1 ns and the signal-to-noise ratio was of 61.1 dB in the RF spectrum. The proposed WS2-SAM opens a promising way for practical fiber-integrated mode-locker for pulsed fiber laser technology.