Topological insulator Bi₂Se₃ based Q-switched Nd:LiYF₄ nanosecond laser at 1313 nm

We report on a1.3 μm Q-switched laser operation based on LD-end-pumped Nd:LiYF₄ (YLF) crystal firstly using few-layer topological insulator (TI) Bi₂Se₃ as saturable absorber (SA). The TI Bi₂Se₃ SA is fabricated by transferring the liquid-phase-exfoliated Bi₂Se₃ nanosheets onto a BK7 glass substrate. After a free-running laser operation, the TI Bi₂Se₃ SA is inserted into the concave-plano laser cavity and finally a stable Q-switched laser operation is achieved with a maximum average output power of close to 0.2 W corresponding to a pulse repetition rate of 161.3 kHz, a shortest pulse width of 433 ns and a pulse energy of about 1.23 μJ. The results experimentally extend the promising application of the 2D material, few-layer TI Bi₂Se₃, in solid state lasers (SSLs).