Several nanosecond Nd:YVO₄ lasers Q-switched by two dimensional materials: Tungsten disulfide, molybdenum disulfide, and black phosphorous

Graphene-like two-dimensional (2D) materials have shown remarkable broadband saturable absorption properties. These materials were successfully applied into mode locked lasers to generate laser pulses with the pulse duration from picosecond to femtosecond. However, these novel materials have not shown good performance as far in another important aspect: Q-switched lasers. Solid-state or fiber lasers Q-switched with broadband absorbers usually generated pulses of one hundred nanosecond to several microsecond, which show weak competitiveness compared to traditional absorbers such as Cr: YAG and semiconductor saturable absorption mirror (SESAM). In this paper we utilized BP, WS₂ and MoS₂ solutions as saturable absorbers (SAs) to construct the passively Q-switched Nd:YVO₄ lasers. The pulse durations as short as 2.86 nanosecond was obtained. To the best of our knowledge, it was the first report that the pulse durations approached several nanosecond level in Q-switched lasers with liquid-form of BP, WS₂ and MoS₂ SAs.