Mid-infrared 3–4 μm emission of Ni2+ doped chalcogenide glass-ceramic fiber

The choice of gain media significantly affects the efficiency of mid-infrared (MIR) lasers and amplifiers. Transition metal ion-doped glass-ceramics (GCs) are attractive laser gain materials as they have the advantages of both laser crystals and glasses. Transparent GC fibers with efficient MIR emission are currently scarce. The emission properties of Ni2+ ion in GCs are generally studied in an octahedral ligand field, where it emits near-infrared light. The emission properties of tetra-coordinated Ni2+ ions are yet to be explored. Herein, we found a chalcogenide glass host characterized by high crystallinity and prepared transparent Ni2+-doped chalcogenide GC containing ZnS nanocrystals by in-situ crystallization. Moreover, for the first time, we reported the broadband MIR 3–4 μm emission at room temperature from tetra-coordinated Ni2+ in chalcogenide GC fiber embedded with ZnS nanocrystal. The fiber losses were measured to be 18.6 ± 1.1, 9.8 ± 0.6 and 11.4 ± 0.8 dB/m at 2.10, 3.39 and 3.80 μm, respectively. The results indicate that the active chalcogenide GC fiber reported herein can be potentially used to develop MIR-tunable fiber lasers and amplifiers.