S-band Q-switched thulium fluoride fiber laser using graphene saturable absorber

Abstract

A Q-switched S-band thulium fluoride fiber (TFF) driven by a 1400 nm laser diode is proposed and demonstrated. The TFF has the advantage of being pumped at 1400 nm, which is an easily available and relatively low-cost pump source, as opposed to conventional pumping at 1050 nm. It has a gain profile from 1440 nm to 1520 nm, and Q-switching is realized with the use of a thin film graphene saturable absorber. The Q-switched TFF laser exhibits a maximum repetition rate and minimum pulse width of 36.3 kHz and 3.2 µs respectively, as well as an average output power and pulse energy of 0.76 mW and 20.9 nJ at a maximum pump power of 230.4 mW. The output pulses are highly stable, and to the best knowledge of the authors this is the first demonstration of a Q-switched TFF laser pumped at 1400 nm.

Passively Q-switched S+/S band fiber laser with copper telluride saturable absorber

“…Similarly, Reduan et al [46] also showed an output with a larger pulse width of 3.8 µs using a molybdenum disulphide (MoS 2 )-based SA than the obtained pulse width of 3.2 µs of this work. The Q-switched laser in this work has the same pulse width as that of the cavity using the graphene-based SA [41], which also showed a lower pulse energy of 35.8 nJ than the laser of this work. From table 1, it can be seen that the Cu 2 Te SA generates among the highest maximum pulse energy and maximum average output power in the S+/S band region, with only the MoS 2 SA performing similarly.…”