Multi-color Q-switched of neodymium-doped all-fiber laser based on tungsten disulfide saturable absorber

In this paper, a Q-switched and three-color operation of Neodymium-doped silica all-fiber laser is realized, in which, a few-layer transition metal dichalcogenides WS 2 is pioneered to be used as a saturable absorber (SA). The compact and simple linear cavity contains homemade fiber mirrors by directly depositing a multilayer coating the SiO 2 /Ta 2 O 5 dielectric films on fiber end-face. In particular, by inserting the WS 2 -SA into the FP laser cavity, it is found that a stable Q-switching operation was achieved with the higher signal-to-noise ratios (SNR) of 60.76 dB, and the shortest pulse duration of 990 ns, as well as the maximum repetition rate of 124.4 kHz. Meanwhile, the maximum average output power and maximum pulse energy are close to 8.9 mW and 71.5 nJ, respectively. This is, the first demonstration of compact WS 2 -based neodymium-doped all-fiber laser operation at 1081.9, 1091.3 and 1100.1 nm.