Broadband saturable absorption responses of few-layered MoSe2 nanosheets for all-solid-state Q-switched lasers

Abstract

Few-layered molybdenum diselenide (MoSe2) nanosheets were successfully fabricated by the ultrasound-assisted liquid phase exfoliation (UALPE) method. It exhibits broadband nonlinear optical (NLO) responses with optical modulation depths of 12.4% and 9.3% at 1.3 and 2 μm, respectively. Based on this, it was transferred onto a quartz substrate, acting as a saturable absorber (SA) to initiate solid-state pulsed lasers. The Q-switched Nd: GdVO4 laser with a minimum pulse duration of 366 ns and a repetition rate of 196 kHz was generated at around 1.3 μm. Meanwhile, the Q-switched Tm: YLF laser with a minimum pulse duration of 200 ns and a repetition rate of 43 kHz was obtained at around 2 μm. The experimental results indicate that few-layered MoSe2 nanosheets have a significant development prospect as a SA in optical modulation with a broad spectral band range at the near-infrared (NIR) band.