200-fs mode-locked Erbium-doped fiber laser by using mechanically exfoliated MoS saturable absorber onto D-shaped optical fiber.

For the first time, we demonstrated the fabrication of mechanically exfoliated molybdenum disulfide (MoS) samples deposited onto a D-shaped optical fiber. The MoS exfoliated flakes were deposited onto a stacked of 1.2 µm PVA (polyvinyl alcohol) and 300 nm PMMA (polymethyl methacrylate) layers and then transferred directly onto a side polished surface of D-shaped optical fiber with polishing length of 17 mm and no distance from the fiber core. The sample exhibited a high polarization performance as a polarizer with relative polarization extinction ratio of 97.5%. By incorporating the sample as a saturable absorber in the Erbium-doped fiber laser (EDFL), bandwidth of 20.5 nm and pulse duration of 200 fs were generated, which corresponded to the best mode-locking results obtained for all-fiber MoS saturable absorber at 1.5 µm wavelength.