LAUSR

Fe2+-doped ZnSe nanocrystals (NCs) were fabricated by femtosecond laser ablation in solution (FLAS). The synthesized Fe2+:ZnSe NCs was characterized by XRD and SEM, which demonstrated the nanocrystalline characteristic of the sample. By spin-coating colloidal Fe2+:ZnSe solution on a multiple-layer dielectric film, a Fe2+:ZnSe saturable absorber (SA) was prepared. Employing the as-prepared Fe2+:ZnSe NCs SA in an Er3+:ZBLAN fiber laser, a passively Q-switched laser was successfully demonstrated at ~2.78 μm, with a recorded minimum pulse width of ~0.52 μs, maximum repetition rate of 127.46 kHz, peak power of 7.30 W and pulse energy of 3.81 μJ. This work shows Fe2+:ZnSe NCs can be successfully fabricated by FLAS, and after ablation Fe2+:ZnSe NCs can be efficient miniaturized SA device candidates for mid-IR fiber lasers and have great potential to be prepared on a fluoride fiber end for a compact all-fiber passively Q-switching laser at room temperature.