2 µm passively Q-switched Tm:YAG pulse laser with a graphdiyne saturable absorber

Graphdiyne (GDY), which possesses the advantages of optical transparency, ultra-high mechanical flexibility and excellent optoelectronic properties, has been used in various fields, such as electrochemistry, storage and flexible electronics. Here, GDY fabricated by the Glaser-Hay coupling reaction serves as an outstanding nonlinear optical material that can produce ultrashort laser pulses from Tm:YAG solid-state cavities. The as-prepared GDY-based device has been successfully utilized as a saturable absorber, displaying that the modulation depth and saturation intensity are ∼12.8% and ∼1.14 MW/cm 2, respectively. The output pulse duration is ∼895 ns and the pulse repetition frequency of ∼180.5 kHz @2007.6 nm. These results provide that GDY is a candidate nonlinear optical material for generating ultrashort pulses, which is of tremendous interest for potential applications in photonic devices and nonlinear optics.