Controllable fabrication of Er ³⁺ -doped chalcogenide glass-ceramic fibers with enhanced mid-infrared emission

Hybrid matrices combining a glass host with acrystalline phase-specifically transparent glass ceramic (GC) fibers are critical for advancing mid-infrared (MIR) laser sources. Here, we demonstrate the fabrication of Er³⁺-doped chalcogenide GC fibers containing LaCl₃ nanophases via a tailored heating protocol. This strategy successfully encapsulates Er³⁺ ions within a low-phonon-energy crystalline environment, yielding a robust emission peak at ∼2.7 µm. Notably, the GC fiber exhibits a 4.5-fold emission intensity enhancement compared with the as-prepared fiber. This optical improvement is attributed to the optimized local coordination environment of Er³⁺ ions resulting from nanocrystal precipitation. Furthermore, numerical simulations utilizing rate and propagation equations confirm the feasibility of achieving 2.7 µm laser output. These findings underscore the potential of these GC fibers as robust candidates for MIR fiber laser applications.