Graphdiyne As a Saturable Absorber for 2-Μm All-Solid-state Q-switched Laser

As a novel one-atom-thick carbon allotrope, graphdiyne (GDY) has attracted wide interest in two-dimensional materials owing to its unique feature with a planar layer comprising sp 2 - and sp-hybridized carbon atoms and a direct natural bandgap. A high-quality saturable absorber (SA) based on GDY was successfully fabricated, and the nonlinear saturable absorption properties were investigated. A compact diode-pumped solid-state passively Q-switched laser based on the as-prepared GDY-SA could be operated at 2 µm. The Q-switched laser delivered a maximum average output power of 1.29 W at a central wavelength of 1908.41 nm with up to 54.8% slope efficiency. A repetition rate of 91.58 kHz and single pulse energy of 23.08 µJ were obtained. This work is the first application of GDY as an SA to generate all-solid-state pulsed lasers. These results indicate that GDY is a promising SA for solid-state pulsed lasers and has further application potential for ultrafast photonic devices in the 2-µm region.