High energy passively Q-switched Er-doped fiber laser based on Mo_0.5W_0.5S₂ saturable absorber

A passively Q-switched Er-doped fiber laser based on a novel transition metal sulfide (TMDs) Mo_0.5W_0.5S₂ absorber is reported for the first time. There are two different types of Mo_0.5W_0.5S₂-based saturable absorbers (SAs) that achieve Q-switching operation, one of which is depositing the Mo_0.5W_0.5S₂ on the surface of the tapered fiber, and the maximum single pulse energy of 172.91 nJ and minimum pulse width of 1.42 μs is obtained. While the other is transferring Mo_0.5W_0.5S₂-PVA(polyvinyl alcohol: PVA) SA film onto a standard FC/APC fiber end face, the high single pulse energy of 246.5 nJ and the minimum pulse width is 1.92 μs is obtained, and the modulation depth of SAs detected by the twin-detector method is 15%. The experiment results show that Mo_0.5W_0.5S₂ can be considered as a promising candidate for pulse fiber laser applications and other photoelectric devices.