Defective molybdenum oxide function as saturable absorber for nanosecond pulse generater servicing Nd3+, Er3+, Tm3+ doped laser emission at 1.06, 1.64 and 1.94 μm

A defective molybdenum oxide (MoO 3− x ) prepared by a hydrothermal and defect engineering approach was spin-coated on the quartz glass and implemented as saturable absorber (SA). The experiment evidenced that MoO 3− x based SA can function as an efficient nanosecond pulse generator, servicing Nd 3+ , Er 3+ , Tm 3+ doped lasers emission at 1.06 1.64 and 1.94 µm. And the shortest pulse duration of 396 ns, 275 ns, and 1.4 μs was achieved on this wavelength with the corresponding maximum peak power of 14.37 W, 33.76 W and 7.94 W. In our study were also observed the optical modulation characteristics as well as the output performance of the passive Q-switch lasers modulated by MoO 3− x SA, which indicates that the modulation depths are 6.5%, 7.6% and 5.8%, respectively, while the average output powers 0.79 W, 1.13 W and 1.6 W. The results confirm that the few-layered MoO 3− x nanosheets can be a promising candidate for pulse laser generation in wide spectral bands, and they exhibit a great stability in an atmospheric environment and high laser damage threshold, which are beneficial to realizing high power laser output.